By on July 2, 2007

dieseldragster.jpgNo wonder the Germans are so gung-ho on sending their diesels across the pond. Europe’s two-decade long diesel-keg party has been crashed by a new generation of super-efficient, clean and cheaper gasoline engines. A royal diesel-overproduction hang-over is inevitable. The Germans’ morning-after solution: send the stinky leftovers to enthusiastic Yanks waiting with open arms, who’ve conveniently forgotten their killer hangover from the last US diesel orgy.

In 1892, an experimental ammonia engine literally blew up in engineer Rudolph Diesel's face. Laid-up in a hospital bed, he pored over Nicolaus Otto’s pioneering work on the internal combustion engine. Diesel identified its weakness.

Diesel tumbled to the fact that the Otto engine’s efficiency was intrinsically compromised by the fact that it mixed fuel with air prior to compression. Too much compression resulted in uncontrolled pre-detonation. Diesel’s solution: inject fuel separately from the air to allow super-high compression and eliminating the need for a throttle (reducing pumping losses). Diesel's engine was roughly 30% more efficient than Otto's. 

In 1989, VW/Audi ushered in the modern direct-injection (TDI) diesel. The group's oil burning powerplant set a high-water mark in the diesel’s long development. With Europe’s high fuel costs, the more expensive (yet efficient) diesel engine could now pay for itself quite easily. The calculation triggered Europe's diesel-boom, resulting in a 50 percent market share vs. gasoline-engined propulsion. 

But Europeans have been paying a price (other than at the pumps): particulate emissions (Particulate Matter, or “PM”) and NOx pollution. Many European cities have serious particulate and diesel odor problems. Several European cities impose restrictions on diesels during PM alerts.

The new generation of “clean(er)” diesels that meet the US Tier2 bin5 standards cut PM emissions substantially, but not completely. Already, there are warnings that PM from “clean” diesels still poses a significant health risk.

The diesels coming our way carry several other penalties, especially versus the gas hybrid. The complicated and expensive NOx catalysts and urea injection schemes (“BlueTec”) cut efficiency by five percent. Meanwhile, the next Prius is projected to be 15 to 20 percent more efficient. And Toyota is bringing down hybrid production costs.

The diesel vs. hybrid mileage/cost gap widens… further. And the “clean” diesel’s just-barely compliant emissions still can’t touch the gas-hybrid’s practically breathable exhaust.

Then there's the elephant in the room: global warming. Clearly, the political winds are blowing against CO2. Diesel fuel has higher carbon content, resulting in 17 percent more CO2 per gallon of fuel burned than gasoline. With the diesel’s efficiency superiority down to 25 percent, a “clean” diesel emits only 13 percent less CO2 than yesterday’s gas engine. And that small gap is… wait… gone.

While the diesel’s efficiency peaked in 1989, and lost 5 percent to PM cleansing, gas engine development is on a roll. Engineers are systematically tackling all the inherent deficiencies that Diesel identified in his hospital bed. (No wonder Rudolf was considered paranoid; maybe he suspected that eventually the Otto engine would catch up.)

A farrago of new gas-engine technologies has converged, which Europeans have been quick to embrace. VW’s 1.4-liter 170hp TSI gas engine is a perfect example of the trend. The TSI starts off with the help of a supercharger (no turbo-lag), and then switches to turbocharging (no parasitic losses). With diesel-like torque and direct injection, it’s the best of both worlds.

A CO2 output comparison with two other similar-output VW engines is telling. Their 170 horse 1.4-liter TSI produces 174g/kms of CO2. Their 150hp 2.5-liter five cylinder engine (US Rabbit only) emits 240g/km. And their 170hp 2.0-liter TDI diesel (not US compliant) produces 160g/km.

American Rabbit drivers are paying a whopping 38 percent efficiency penalty compared to the Euro-Golf TSI, as well as giving up gobs of torque and twenty horsepower. If VW’s 170hp TDI were “cleansed” to T2b5 standards, its CO2 output would be no better then the gasoline TSI.

And that’s just the jumping-off point. Start-stop technology, full valve control, and stratified direct-injection offer anywhere from 10 to 25 percent further improvement potential. Combine these goodies with mild-hybrid assist/regeneration, and the diesel party’s kaput. No wonder the Germans are all hard at work on mild-hybrid technology. It’s their best shot to keep up with Toyota’s CO2 meister, the Prius (102g/km).

A study by the consulting firm AT Kearny confirms the diesel's demise. It predicts that only 25 percent of Europeans will find diesels an attractive economic proposition by 2020.

Have Rudolf Diesel’s paranoid nightmares come true? Not totally. Diesels are a welcome mix to the party for larger vehicles that spend a lot of time on the open road. Count on GM’s new 4.5-liter “baby” Duramax diesel to be more popular with the light-truck crowd than the gas hybrid option. But when it comes to smaller vehicles, the numbers just don’t add up.

Although Rudolf Diesel’s engine WAS intrinsically more efficient, it turns out that Otto’s engine is a lot more clever at learning new tricks.

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119 Comments on “The Truth About Diesels...”

  • avatar
    Glenn 126

    Thanks for being so open minded about the Prius. But then again, facts are facts.

    Consumer Reports imported a diesel SMART car from Quebec (i.e. it wasn’t US compliant – not even for non-California states) and gave it their test-over, and it obtained 42 mpg. They got 44 mpg with their tested 2005 Prius, and the Prius is obviously a lot more car than is a 2 seat SMART.

    One thing that perplexes me no end is the fact that diesel fuel and gasoline both come from crude oil – so why was it that, when gasoline was $2.19.9 locally awhile back, diesel fuel cost $2.79.9 – but when gasoline went to $3.66.9 diesel was only $2.96.9?

    Anyone out there in the oil industry want to address that one?

    One other minor advantage to diesel is that at least when you put bio-diesel into the fuel tank, you don’t lose MPG as happens with virtually every car I’ve ever driven since 1979 and tested E10 in. I generally lose 7% to 20% MPG.

  • avatar
    Paul Niedermeyer

    Glenn 126:

    The most credible answer regarding diesel vs. gasoline cost is refinery capacity and demand. Diesel fuel demand has grown quite strongly over the past 5-7 years, creating tight supply, and high prices. The current run-up in gas prices is (supposedly) due to gasoline refinery problems.

    In any case, the US petroleum industry is not ready for more diesel consumption, and a substantial increase in diesels on the road would just push up diesel prices higher.

  • avatar

    Interesting article. Autobloggreen came to the same conclusion (through a series of articles here & there) that gasoline tech will improve a lot but diesel tech has pretty much matured. Let’s see if Honda can improve diesel tech further.

  • avatar
    Paul Niedermeyer

    monteclat: “Let’s see if Honda can improve diesel tech further”.

    Honda makes an excellent diesel for Europe, but it’s not more efficient than all the others. Sorry, but waiting for a “Honda miracle” is misplaced hope.

  • avatar

    So how does biodiesel compare to regular diesel in terms of particulate matter, NOx, and CO2? Better, worse, about the same?

  • avatar
    Paul Niedermeyer

    Jonathon: Interesting that you should ask. A recent (and scary) first study from Europe analysing biodiesel exhaust shows a very disturbing high number of carcinogenic substances. This was a blow to the biodiesel contingent.

    Apparently, the super-high temperatures of combustion do some nasty things to bio-diesel. Kind of like baking/frying creates bad substances in cooking oil, but worse. It needs further study.

  • avatar

    It’s possible that the TDI Rabbit could be cleaned up by a system that would collect the particulates, compress them into centimeter-sized spheres, and store them in a container for later disposal. However, who could guard against the “smart” asses who would leave the container off, thus resulting in Diesel Rabbits leaving a trail of these pellets…

  • avatar
    Paul Niedermeyer

    Jonathon: My link was for an article about the effects of burning straight vegetable oil in diesel engines, not biodiesel.

    There is not enough research to provide a clear picture of biodiesel exhaust vs. straight diesel. Some early work suggests advantages (for biodiesel), but there is not yet a deep understanding of the chemical changes that happen to some of the organic compounds. It may be problematic, like the straight vegetable oil. In anycase, we can’t grow enough to solve the problem.

  • avatar


    The NOx content of BioDiesel is directly tied to the feedstock that the BioDiesel was made from. Some vegetable sources make for very high NOx, and other bring it down to near zero.

    Unlike gasoline, Diesel fuel of any sort emits NO CO2.

    Particulate from BioDiesel is the same as petro-Diesel, and is mitigated completely by rainfall as it is heavy and will not stay suspended in the air with sufficient moisture.

    Short of a 100% hydrogen- or solar-powered vehicle NO engine blows sunshine and kittens out the tailpipe. On the scale of relative evils, an engine running on BioDiesel is far better than any petroleum-powered machine.

    At least with Diesel, you have alternatives, ALL of which can be home-brewed if you choose. You cannot say the same with gasoline.


  • avatar
    Paul Niedermeyer

    chuckgoolsbee: “unlike gasoline, Diesel fuel of any sort emits NO CO2”.

    Chuck, sorry, but ALL diesel fuel emits CO2, as does burning any carbon based product. In fact, diesel emits 17% more CO2 per gallon than gasoline. That’s one of the key points of my article, and a negative for diesel in the push to reduce CO2 emissions.

  • avatar

    Logically a hybrid diesel electric vehicle would be an optimum choice. The diesel ability to produce power at low RPMs for long periods of time would be ideal in a start/stop hybrid or a full hybrid. Combine all the other energy saving technology in the Prius (low resistance tires, slippery design, etc with a diesel engine and we’d probably see a 10% improvement in economy.

  • avatar

    Chuck- I am with you here/ Bio fuels can make the diesel a good alternative since growing the fuel consumes CO2. Combined with the other emisisons systems a 100% bio, or a bio blend makes diesel an excellent green engine.

    On the flip side, according to studies by UC Berkeley, there is not enough arable land in N. America to grow enough plant matter to replace fossil fuels, still, we can do what we can and use blends.

  • avatar
    Glenn 126

    A drop-in gasoline substitute is available, and can be grown. It’s called Butanol. I understand BP in the UK are looking into mass production now. The conversion efficiency is something on the order of 70% (vs approximately 30% conversion efficiency for ethanol from corn) and the BTU’s are 5% less than gasoline (vs. 30% less for ethanol). Butanol (or bio-butanol if it is grown and made into Butanol) can also be pushed through our current petroleum pipelines, again, unlike ethanol.

    Butanol is a 4-carbon chain alcohol (and deadly to imbibe). See

    Butanol is one reason why, in my humble opinion, the government should NOT emulate the soviets and try to force solutions (such as corn-grown ethanol) onto a “free” marketplace.

  • avatar
    Paul Niedermeyer

    saabophile: “logically, a hybrid diesel electric vehicle would be an optimum choice”. If fuel cost $10/gallon, you would be right.

    Between the much higher cost of a clean diesel ($2k to $3k), and the cost of hybridization ($2k to $3k), you would end up with a car costing so much more it would take maybe 20 years or more to amortize the costs (at today’s fuel costs).

    Mild diesel hybrids are coming in Europe (Peugeot 308, MB S-class), but they won’t be economically viable in the US, and might not be in Europe.

  • avatar

    Note how diesel and gasoline engines are converging. A staged turbo, direct-injection gasoline will prove to be more efficient in the end. Perhaps a higher carbon gasoline summer-blend will be produced to aid efficiency.

    On a personal note: I *HATE* turbo-lag…Worse than torque-steer.

  • avatar

    Oh…And…Great write-up Paul!

  • avatar
    Steven Lang

    chuckgoolsbee did a better job nailing the ‘biodiesel’ alternative than 90+% of the rantings I’ve seen elsewhere.

    I’m a big fan of biodiesel… but it needs to be refined to the point where the quality is consistent.

    Most biodiesel applications offer lower fuel economy than straight diesel. However, if you use top grade bio-diesel in combination of bio-diesel, there can be a substantial decline in the overall pollution that takes place.

    Yes, this is only a partial solution. But it also happens to be a heavily underutilized one that can improve the environment and our oil dependency.

    I think the diesel/hybrid combination may turn out to be the new standard. A VW Lupo of the late 90’s can attain a real world mileage of 70 to 75 mpg and the inclusion of a battery for city traffic would cut overall emissions immensely. For a small city commuter, that may be the most efficent opportunity in the marketplace.

  • avatar

    In 2001 the EPA did a study of Biodiesel made from soybeans. At 100B, biodiesel produces 67-68% less unburned hydrocarbons, 45-50% less Carbon Monoxide and Particulate matter (I’m giving these numbers in ranges, because I’m just looking at a graph rather than searching through the 126 page document), and 10% more nox.

  • avatar

    “The NOx content of BioDiesel is directly tied to the feedstock that the BioDiesel was made from. Some vegetable sources make for very high NOx, and other bring it down to near zero.”

    Do you have a source for this? I don’t think it’s true. You guys here are probably sick of me getting into the details, but I’m a chemist, and as a result, I’m always thinking of the chemistry going on in a process.

    In any IC engine, you have the stuff you want to burn, which are hydrocarbons (Gasoline, Diesel Oil, Biodiesel, Veggie Oil, etc) extra stuff that’s with the stuff you want to burn (Sulfur, and other impurities), stuff the government mandates to “clean” up the emissions (Ethanol, MTBE, etc), and the atmosphere (Nitrogen, Oxygen, and small amounts of whatever else came in through the intake).

    The simple combustion reaction is

    Hydrocarbon + Oxygen –> Water + CO2

    So In the best case scenario, burning gasoline, diesel, biodiesel, or whatever you only make Water and CO2. Nothing bad about either of those (except MAYBE CO2 – but I’m going to reignite that debate). You also get a little CO if there’s not enough oxygen to go around. But CO –> CO2 is easy for the catylitic converter to take care of.

    Now where does the bad stuff come from.

    1) There’s lots of sulfur dissolved in crude oil when it comes out of the ground. This is normally a good thing as it makes the oil more lubricative but it’s a bad thing when you burn it because it ends up making SO2 out of the tail pipe which mixes with atmospheric water to turn into sulfuric acid (better known as acid rain). So by removing sulfur from our fuel (ever heard of light sweet crude? sweet means low sulfur) we get less acid rain, which is generally agreed upon as a good thing.

    2) The second bad thing is particulates. Particulates are generally called “soot”. While they are carcinogenic, they’re not THAT bad. They’re big (i.e. you can see them as opposed to the nasty stuff you can’t see). Your body does a good job filtering big things before they can cause a problem. So in general particulates aren’t that bad because your body can filter them. And if we wanted to they’re big enough that we can filter them on their way of of the tailpipe too. Particulates are an easily solvable problem if someone would put their mind to solving it.

    3) The last bad thing I can think of right now is NOx. So where does the NOx come from? There is no nitrogen (or very very little) in the fuel we burn. But the atmosphere is 80% nitrogen, so that’s where it comes from.

    Nitrogen + Oxygen –> NOx

    But it takes lots of energy (heat) to make NOx out of nitrogen and oxygen. So if you lower combustion temperatures you get less NOx and if you raise combustion temperatures you get more NOx.

    So really NOx production doesn’t depend on the fuel (directly), but on how the fuel is burnt.

    Lean mixture: More Oxygen than Fuel –> Burns hotter –> More NOx less CO

    Rich mixture: Less Oxygen than Fuel –> Burns colder –> More CO less NOx

    (Side note – in a gasoline engine, the oxygen sensor keeps oscillating the mixture between Rich and Lean so that the engine alternates between NOx and CO production. The cataylic converter takes the O off of the NOx and puts in on the CO which results in Nitrogen and CO2 as products which are much less harmful than the incoming NOx and CO)

    Anyway. here’s the conundrum: Unlike a gasoline engine, a diesel engine always runs lean. As a result of the lean mixture and the high compression (which is why the diesel is more efficient than the gasoline engine) the cylinder temperatures are very high. That means that it makes NOx, and lots of it.

    So if you want to reduce NOx you need to reduce the combustion temperatures. The only (easy) way to do that is to reduce compression and now were back to gasoline type efficiencies. I bet it could be done with water injection, but I don’t think people want to fill up a gas tank and a water tank.

    Likewise, with all the direct injection gasoline engines coming out, they’re going to be raising compression ratios to get more efficiency, and those engines are going to be making more NOx.

    NOx is something we really can’t get rid of easily because there’s so much Nitrogen in the atmosphere, we’ll never keep it out of the cylinder. We can convert it to CO2 and N2, but that requires CO to steal the O off of the NOx, and unless the engine runs rich, you don’t get that (That’s what the Regen in the new Powerstroke diesel does. Every so often, the computer just dumps lots of fuel in and cuts off the intake, that makes a bunch of CO which then cleans the NOx out of the catalytic converter – and of course reduces your MPG)

    Ok, that was a long post and I started to ramble. But I hope that you can now see that it’s not a simple problem. There are many competing variable that we have to work with and some of them are in direct opposition to others.

  • avatar

    In North America diesels are for trucks, where they do a good job, now with a catalytic converter and EGR.

    In Europe diesels became popular in cars since the price of diesel fuel was substantially less than gasoline.

    The diesels in European cars that come to North America are very quiet, smooth, more economical than the equivalent gasoline engine in the same model car. Plus the diesels have incredible low end torque which is an interesting feature.

    There has always been a love / hate relationship with diesel powered cars in North America. It will continue for a few more years.

  • avatar
    Martin Schwoerer

    A few additions to an excellent article —

    – The Diesel torque-shove that people love is, to some degree, achieved through overboost. Unfortunately, a Diesel on overboost belches smoke (less politely, one could say it farts). The overboost belch is not an element of most emission ratings but is a real, and probably unhealthy, annoyance. (Especially when you are on a bike or motorcycle, behind one of those acceleration junkies).

    – Diesel is nasty — smelly and sticky on a gas station forecourt. It sticks to your shoe soles and is slippery and doesn’t wash off in the rain. Your hands stink upon filling up.

    – For the enthusiast, Diesels are quite often downright unpleasant to drive. The acceleration of a shopping cart up to 1500rpm, then a great surge of torque up to 3000rpm, but nothing after 4000: I don’t like ’em.

    – People like to con themselves into thinking that Diesels are economical, but higher purchase prices and higher repair costs mean that you have to drive most Diesels more than 15k miles a year for them to make any sense at all.

  • avatar

    “Lean mixture: More Oxygen than Fuel –> Burns hotter –> More NOx less CO”

    This is why Audi/VW FSI engines do not go lean burn in the States…Can’t pass 2007 emissions law.

  • avatar

    I dunno. Last summer I drove the Citroen C6 diesel and the Audi A8 diesel, impressive rides, both. The carbon content issues aside, it does seem that a litre of diesel in either of those 2 cars goes farther than a litre of petrol would in the Otto cycle equivalents. Physics is physics. I’m just guessing, but one easily imagines various boffins in Japan, Germany and yes, even the US, hard at work on the next generation of diesel-hybrid systems…

  • avatar

    Paul, you are right about CO2… I was thinking/reading “carbon monoxide” while typing/not recognizing “carbon dioxide.”


  • avatar

    A few other things to consider:
    -The well to tank efficiency of diesel is higher than gasoline i.e. it takes less energy to get it to you
    -Better metering of fuel can do a lot to reduce particulate emissions. Boost has nothing to do with it; it’s the injectors putting too much fuel into the cylinder when you mash the gas pedal.
    -The theoretical thermodynamic efficiency of a Diesel cycle is higher than an Otto cycle. Stratified charge gasoline engines operate on a Diesel cycle instead of the Otto cycle.
    -I believe all diesel in the US is now low sulfur

  • avatar

    Martin said:
    “People like to con themselves into thinking that Diesels are economical, but higher purchase prices and higher repair costs mean that you have to drive most Diesels more than 15k miles a year for them to make any sense at all.”

    I paid $17k for a VW Jetta TDI in 2002. I have driven it 110,000 miles with less than $1000 spent for servicing it so far (Service, not maintenance. I’m obsessive about oil & filter changing and basic maintenance, which i do myself.) One third to one half of the fuel I have used in the car I have made myself, at almost zero cost. If I were to average out the monies I’ve paid for fuel since 2002 I’d say it was well under $2 per gallon. The car averages 48-52 MPG, and most of my driving is on highways.

    So, some top of my head math: Roughly 2200 gallons to travel that 110,000. So around $3960 paid into fuel.

    Had I been driving an 18 MPG SUV all these years for all those miles at $2.45 a gallon I would have paid almost $15,000 in gasoline.

    I’ve almost saved the entire purchase price of the car in fuel savings alone. Some con eh! =)


  • avatar
    Paul Niedermeyer

    chuck: your examples is taking an apples to oranges comparison to an irrelevant extreme. Europeans do their math carefully, and the extra cost of the diesel doesn’t pan out for less than the annual mileage Martin gave. Even less so with our lower fuel costs.

  • avatar

    I’ve almost saved the entire purchase price of the car in fuel savings alone. Some con eh! =)

    Until the gov’t comes after you for all the fuel taxes you’ve cheated them ;)

  • avatar

    Thank You, Gracias, Danke, Merci for this wonderful bit of clearly stated knowledge. Its like a breath of non-polluted mountain air.

    Thank you also Miked for your review of chemistry for us non-chemists. I knew there was reason I should have studied harder when taking chemistry, I have been at a loss more than a few time when trying to understand the world around me.

  • avatar

    I’ve got an MB GL320 diesel on-order. It costs $2500 less than the gas GL450. (To be fair, it’s got a V6 vs. the gasser V8, which accounts for the up front savings.) So I’m saving $2500 up front and saving a pile of money on fuel via better fuel mileage and, for now, cheaper prices at the pump. I can’t envision a scenario whereby I’ll spend more money over the life of the GL320 compared to the GL450 which takes Premium gas. No matter how many or how few miles I drive.

    I’ve read and re-read the analysis of NOx, CO, CO2 etc in the comments and came away very confused. I think every side of this arguement has facts and statistics to back up their assertions. In my simple mind, it’s very simple. I’m spending less up front, I’m getting more miles per gallon of “petrolium product”, I’m using a fuel that takes less energy to refine and I’m emitting less CO2 per mile. The NOx and PM are open questions but they’ve been knocked down considerably, even without the ad-blue in my 2007 GL320. So, on the whole, it seems like a good thing. And if gasser engines are so much better by 2020, then that’s fine, I’ll be ready to replace the GL320 by then anyway.

  • avatar

    “In my simple mind, it’s very simple. I’m spending less up front, I’m getting more miles per gallon of “petrolium product”, I’m using a fuel that takes less energy to refine and I’m emitting less CO2 per mile.”

    Yes, and I think that’s the correct view to have. Over all diesel is the better choice when you’re talking about miles driven per amount of energy required to get it to you from the well. It generally also wins on miles driven per dollar, and miles driven per amount of CO2. It may lose on miles driven per amount of NOx. But in the end you need to optimize on what you care about.

  • avatar

    SUV’s – SUT’s – Pick Ups should all have a diesel option at a reasonable price to raise the fuel economy of these vehicles.

    Just like commercial trucks have all gone from gas to diesel, the same conversion should be going on with all these “trucks” that are used as cars.

    Beyond cross overs every manufacturer should be offering a diesel option or only diesel in the bigger SUV’s and pick ups.

  • avatar


    Another thing many diesel-haters out there forget when they compared the technology of Benz-engines (Otto cycle) vs Diesel is that the Otto-cycled ones have had 40 year longer technological development curve.
    May I remind you that the diesel engines in the MB in the 70 were not fundamentally different that they were in the first MB engines in the 30. If you do the same comparison for gasoline an engine from the 1930 and one from the 1970 are 2 different beast entirely.
    Diesels have come a long, long way since the GM fiasco in the 80 and when they catch-on the many subtleties that gas engine have enjoyed so far, gas engine are not going to look that great.

    The example of the super charged and turboed gas engine above is pure BS!!!! You can do the same with a diesel engine for that matter and have no turbo lag as well, you can even do that with a Variable Vane turbo or a twin turbo setup. You argument does not hold.

    Another argument that does not hold is the one that mentionned that Diesel produces more cO2 per gallon than Gasoline… well duh!!!! is also 25% more nergy dense, the comparison only holds if you compare kg of CO2/kW or Btu in the liquid and at the wheel.

    Thermodinamically Diesel engines are only up to 10% more efficient than gasoline engines.
    Diesel fuel holds 25-30% more usable energy per gallon…
    Even is gasoline engines become complex enough to reduce the efficiency gap they will never, ever manage to fill the gap of content of energy per gallon!!! and that is the bottom line.

  • avatar

    Now the nature of the diesel engine will forbid it to ever ever be cleaner than the gasoline engine.

    So the question is not if Diesel or Gasoline are better or worse than the other. The question is what as a society will be the choice given the advantages and disadvantages of either.
    Diesel more efficient, but heavier and dirtier.
    Gasoline lighter built, cleaner but less efficient.

  • avatar

    I have heard that part of the reason for diesel’s popularity in Europe is because it is taxed less than gasoline – the government does not want to piss off the truckers. Anyone know how true this is? I have seen it come up every now and again when diesels are discussed.

  • avatar
    Paul Niedermeyer

    rashakor: You mised the point about the supercharger/turbocharger combination. It allows one to use a much smaller gas engine (VW’s 1.4 TSI, for example) to replace a larger gas engine. The smaller one will run substantially more efficiently, and thus it approaches diesel efficiency.

  • avatar

    The primary reason for diesel’s popularity in Europe is the European truckers’ lobby. Because of this lobby, diesel cannot be taxed through the roof, like gasoline is in Europe, making diesel relatively cheap. European carmakers have responded by producing diesel cars; but in the absence of government intervention like in the US, diesel cars do not make much sense.
    Biodiesel doesn’t make any economic or environmental sense at all – biodiesel is a farmer subsidy program.

  • avatar

    For those who are more concerned about US dependence on foreign oil than they are about CO2 emissions . . . coal can be converted into a liquid fuel that can be used in a diesel engine, though not in a petrol engine. Granted, I believe the tech to do so still requires much development as it’s not a very efficient conversion. And of course it does NOT address the CO2 problem. But it does help make the US self-sufficient for motor fuel . . . I heard a quote that called the US the ‘Saudi Arabia of coal’.

  • avatar
    Justin Berkowitz


    Thanks for a great article. Up to your usual high quality standards.

    Although I agree with you about diesel versus ultra-efficient gasoline engines (like VW’s TSI), I start to diverge on the hybrid issue. They make more sense than even diesel in some cases for someone leasing the car for 3 years, but they most definitely have not proven anything in the long term. Diesel engines have a reputation for longevity in the U.S. In part, this is because they are more durable than petrol engines. And in part it’s because eccentric fools buy diesel cars and those people are more likely to be fastidious maintainers.

    In spite of all of this, I think many of us are very concerned about (1) the long term durability of hybrid cars and (2) the ecological impact of the battery creation and eventual disposal. These questions are not answered, nor can they easily be answered right now.

    What we do know is that with proper maintenance and investment – two things to which “buy-use- trash” Americans are becoming increasingly hostile – diesel engines can have a healthy 250,000 mile lifespan.

    Gas engines, of course, can also last a long time – my daily driver right now is a petrol V8 with 202,000 miles on it. But the more technology we add (like super-turbo chargers), the more there is to break. The more expensive it is to fix, the more cars just get trashed instead, the more spare parts that get trucked across the country and flown by jet over the oceans.

    I don’t mean to sound like an insufferable hippie at all. Rather, I’m trying to highlight that it’s a very, very small look at the puzzle to compare engines on the basis of “mpg” or particulate emissions per mile driven.

  • avatar

    Even coal gasification – which was used by the Germans during the second world war – is just another of a range of economically infeasible options, given the low price of oil at this time. US dependence on foreign oil is largely a figment of paranoia and xenophobia; oil comes from a wide geographic range of sources and no conflict, unless of unimaginable scale, will alter the global market for oil dramatically.
    A reasonable cautious strategy is to not drill in the Alaskan refuge and leave the oil there for the improbable case of a global catastrophe.
    That is not to say there is not a case for increasing taxes on gas. The US may be caught off guard and be stuck with inappropriate technology if the inevitable – rising and gas oil prices – will start to become more prominent. But this Ph.D. economist cannot see anything but emotional motivations for the use of subsidies, biodiesel, ethanol, or coal gasification.

  • avatar

    Glenn: Easy. Different demand levels and fractional distillation.

    Demand is pretty self-explanatory. (The demand levels also explain why diesel goes up in the winter when gasoline goes down – not because more oil is “turned into diesel instead of gasoline”, but because more of the base oil is being burned in the northeast as home heating oil.)

    As for the distillation… in a barrel of crude, there are what carbon-chains there are.

    Some of them are gasoline-length, some are diesel-length (others are shorter (petroleum gas), in between (kerosene), or longer (lubricating oil, bunker fuel)).

    The only way to change the proportions is relatively expensive chain-cracking or joining, which raises prices if you have to resort to it.

    The cheapest state, all else being equal, is where demand is proportional to the proportions of each in the output from the oil.

  • avatar

    The South Africans have been producing oil from coal for 50+ years. Note that doing so costs ~$35-40/bbl, so for much of that time it was a political “you can’t sanction us” statement. Now, of course, SASOL is making money hand over fist.

    As a Ph. D. economist I’d like to hear your take on the last sentence…

  • avatar

    Paul, I must have missed something because your 12th paragraph, about CO2 comparison, confuses me. You say that the TSI engine produces 174 g/km, and that the TDI engine produces 160 g/km. With those numbers, the diesel is already producing less CO2 than the TSI, but you say that cleaning the diesel up would result in no better emissions than the TSI. If the TDI starts out cleaner, cleaning it further can only widen the gap in favor of the diesel.

    Did you jumble the CO2 outputs? It seems likely the 240 g/km was supposed to be attached to the diesel, and the two smaller numbers belong to the gasoline engines.

  • avatar

    Good article, Paul. I’m intrigued by the VW 1.4 liter TSI engine you mentioned. Maybe one of the European reviewers can let us all know if it’s as cool as it sounds.

  • avatar

    If you stop fuel production at the diesel stage at the refinery, you save 12% of your imported raw material – which is a huge number.

    I’ve seen diesel engines run on pulverised coal and on COW (coal/oil/water) as fuel in mining operations.

    The point being that diesels will run on almost any combustible fuel and in the long run that may prove to be a huge advantage.

    At least the diesels don’t need tune ups very often and won’t need $5000 batteries or $? electric motor replacements.

    Hybrids are as much a dead end as steam engines have proved to be.

    And who would have thought that in 1930?

  • avatar

    As you note, coal gasification in South Africa was extremely heavily state subsidized, in order for South Africa to be able to achieve energy independence during Apartheid. If coal gasification or liquefaction could be done profitably, then there would be plants sprouting up all over West Virginia as we speak, and the US would be the Saudi Arabia of the world. It simply isn’t going to happen, according to any analysis I have read.

  • avatar
    Paul Niedermeyer

    crazybob: CO2 output occurs regardless of how the exhaust is cleansed of particulates. It’s the intrinsic primary result of all combustion. What I was saying about the TDI engine is that when diesels have their particulates “cleaned”, that process (blue-tec, etc) decreases the efficiency of the engine, thereby increasing its CO2 output.

    philbailey: “hybrids are as much of a dead end as steam engines proved to be”.

    I’m going to speculate that if you were around in 1930, you would have said the same thing about diesel locomotives (“dead ends”), especially since they’re all practically hybrids (diesel/electric).

  • avatar


    Wait and see and I told you so, are not very satisfying sentiments. But if you want to put $100 on it and get back to me in five years, I might have to crow, but I’ll try not to.

  • avatar

    Rashakor: Another argument that does not hold is the one that mentionned that Diesel produces more cO2 per gallon than Gasoline… well duh!!!! is also 25% more nergy dense, the comparison only holds if you compare kg of CO2/kW or Btu in the liquid and at the wheel.

    Thermodinamically Diesel engines are only up to 10% more efficient than gasoline engines. Diesel fuel holds 25-30% more usable energy per gallon…Even is gasoline engines become complex enough to reduce the efficiency gap they will never, ever manage to fill the gap of content of energy per gallon!!! and that is the bottom line.

    The relative energy density is only important in determining how much space must be sacrificed to gas tank, and maybe price. by far the most important thing is relative CO2 emissions. If diesels lose that edge, they lose their biggest raison d’etre.

  • avatar

    Speaking of Apples-to-oranges, I think it’s a little unfair to compare diesels which are available today (or within the next couple of months), with some hypothetical gas engine of tomorrow. The TSI is an interesting engine, but if you’re going to critique diesels for drivability, why not mention the fact that the TSI’s main fault has been it’s non-linear power delivery?

    One thing is certain, diesels and gas engines are becoming more and more similar: turbocharging, direct injection, etc. But they aren’t at efficiency parity yet.

    I think it’s more than a little disingenuous to phrase the argument in a way that makes it sound like the european mfg. are dumping their useless, unwanted diesels on an ignorant public, when today, and for at least the next couple years, diesels will have an efficiency advantage.

    Some things may change this: HCI, Li-ion batteries, plug-in hybrids. But all of those things are the proverbial “3-5 years away”, which is just engineer speak for “god only knows”. Diesels are (more or less) here today.

  • avatar
    Paul Niedermeyer

    andyduncan: The TSI is in production, and tests praise its almost perfectly linear power delivery (thanks to its duplex forced-induction).

    The diesel boom has already peaked in Europe. The manufacturers are bringing new “downsized” gas engines to the market, and there is a lot of interest in them. That’s not to say that the decline of the diesel will be particularly rapid.

  • avatar
    Martin Schwoerer

    The TSI: everybody praises it except for Jeremy Clarkson, who hates it. It is probably pretty OK, and VW probably spent a pretty penny in convincing people to discount its flaws. In any case, the concept sounds forward-looking.

    Hybrids: virtually every German manufacturer is working on them and there will be a load of presentations at the upcoming (September) Frankfurt auto show. It seems even Porsche will push a hybrid Cayenne! Watch this Website.

  • avatar

    “TSI starts off with the help of a supercharger (no turbo-lag), and then switches to turbocharging (no parasitic losses).”

    How does it engage/disengage the supercharger? I’d like to see the plumbing on this. Is the turbo having to suck air through the dead weight supercharger when it’s not being used?

  • avatar

    And check out Ford’s TwinForce Technology.

  • avatar

    I don’t have to look hard to find negative press on biofuels, including biodiesel. Even from ‘waste’ products, it’s still a case of eating your own waste stream, i.e. totally dependent on the very inefficient and resource-intensive system already in place.

    Top UK scientist calls biofuels (especially biodiesel) scam:

    Study warns against biodiesel fuels
    U.S. scientists say biodiesel fuel won’t drive down global warming and it might increase rather than reduce greenhouse emissions.

    Environmental warning on biofuels:

  • avatar

    The TSI engine from VW looks very cool, and it certainly gets excellent numbers as far as carbon-dioxide volume/distance. The TSI does not, however, get anywhere near the mileage that the diesels (in the form of the TDI engines) get. For example, in the Golf the 1.4 TSI engine is rated between 38.7 mpg (imperial) and 39.8 mpg, depending upon transmission selection. The 2.0 TDI, on the other hand, is rated between 44.7 mpg (imperial) and 51.4 mpg (numbers taken from At the high end, the TDI is ~29% more fuel efficient…

    The TSI is new technology, so it may improve with time, but it’s also very complicated (two forced induction systems) and might not lend itself well to the typical American driver maintanence pattern. Based upon the fuel efficiency numbers, I still think that diesel engines are a compelling alternative that I’d like to see offered in the US for passenger cars.


  • avatar

    Paul – excellent article; you sent me to for the definition of “farrago”.

    One note which seems to be escaping all in a search for higher efficiency is a general reduction in mass which any engine, diesel or gas, must push around. Ultimately, overall energy efficiency is tied inextricably to the issue of mass as well as the efficiency of the powerplant. If we apply taxes in a manner which corresponds to the total efficiency of the vehicle, the result could well be a swing to more efficient vehicles regardless of powerplant. It has become obvious to local power companies that it is cheaper to “incent” folks to buy more efficient appliances than it is to build new powerplants; perhaps the same principle can be used with cars. This is not to argue that folks should not have the option for a 2.5 ton SUV, but that the real cost should include the cost of procuring oil from unfriendly sources.

    This is one reason I found it hard to buy into the original Prius vs its lightweight Echo non-hybrid counterpart. Surely the overall efficiency of the Echo was better when one considers all of the environmental considerations.

  • avatar


    The doomsayers about biofuels all hang their complaint on the idea that biofuels will REPLACE petroleum… which is patently absurd. There is no possible way that will ever work, and nobody knows that more than a BioDiesel user or producer.

    BioFuels are not a replacement for petroleum, they are however a fine way of extending the supply of petroleum for 20-50% longer.

    In my case, I collect waste oil from restaurant deep fryers that was going into a landfill and using it (mixed with petro-Diesel from my local Tesoro-Alaska retailer) to run my car. That is extending a waste product into something very useful. If you want to condemn me for that, so be it. But from my perspective it seems I’m merely leaving more petroleum for everyone else, and perfuming the air with eau de pomme frites… which I think is a good thing. ;)

    I didn’t compare apples and oranges. I compared real world, actual experience living with, and driving a Diesel car, along with home-brewing fuel… as an alternative to driving around in an average gasoline-powered SUV getting about 18MPG. It is a valid comparison as I have seen it happening all around me on my daily commute since I bought this car. A coworker of mine who lives the same distance from the office as I, but in the opposite direction used to drive a Jeep Grand Cherokee and he & I compared fuel costs regularly (he now drives a motorcycle!)

    It was no more an apples/oranges comparison than your writeup comparing TDI vs. TSI.


  • avatar
    Ashy Larry

    I don’t have much to add to this excellent article and comment debate other than to say it’s funny how writers for a site founded by Robert Farago seem to use the word “farrago” more frequently per words printed than anywhere else. In fact, I can’t think of a time when I have seen that word used even once outside ths site. Must be a clever nod to the founder. :)

  • avatar
    Glenn 126

    We’re forgetting the Atkinson Cycle engine, as opposed to the Otto Cycle or Diesel Cycle.

    Most Toyota and all Ford full hybrids currently use the Atkinson cycle engine.

    The efficiency of my Prius at over 40 mph attests to a) the aerodynamics of the car and b) the Atkinson cycle engine. (Over 40, the Prius electric motors alone generally do not operate to power the car unless it is on a downhill grade).

    In April, my sis-in-law visited us from Scotland, and we three drove to/through the Upper Peninsula of Michigan and then on home, and obtained over 56.5 mpg in my 2005 Prius over literally 500-600 miles. That’s with 3 adults, several hundred pounds of luggage and food, two guitars and tons of cameras and equipment. Truly a mid-sized car inside, where it counts. We were all comfortable.

    Some of the reasons we got such good mileage were also a) the A/C was not on (temps ranged from 40’s to low 70’s) b) the snow tires were off c) speed limits were 55 mph on 90% of the roads d) I know how to properly drive.

    The Atkinson cycle has a big disadvantage in that it produces little torque (accelerative power) compared to an Otto and especially compared to a Diesel cycle engine; however, this makes it “ideal” for full hybrid use since electric motors are the yin to the Atkinson yang – and produce maximum torque at zero RPM.

    The Prius Atkinson cycle engine has a 13 to 1 expansion ratio on the power stroke and a 10 to 1 compression ratio on the compression stroke, which is facilitated by intake valve timing which partially refills the intake manifold, providing self-supercharging for the next charge.

    BTW in regards to hybrid car batteries, I’ve seen comments all over the net for several years – and I can say that I’m confident in Toyota and Honda to do batteries right, and that I understand the Prius taxicabs in use (most of which are in Canada – tough conditions!) last 250,000 miles before being replaced – as in they don’t replace the batteries, they replace the cabs! Toyota says “batteries last the life of the car” and it appears they mean what they say. The batteries also have a bounty on them and all salvage yards know it – so the valuable materials will be recycled. Interestingly, virtually all salvage yards are profitable – unlike the Big 3!

  • avatar

    I am astonished by the lengths that Americans (particularly) go to not to drive smaller more fuel efficient vehicles, or just go slower on the interstates.

    I have reduced my average speed to the speed limit. My gas milage inproved by about 30%. I am passed like i’m standing still by humongous suv’s and pickups going at least 80 or 90 mph. These people do not care much about gas prices i guess. Hell, i used to be one of them. NO longer. There are those who want me to go faster. To hell with them. They are not paying my fuel bill.

    It seems to me that if people were really serious about saving fuel in ANY form, they would be doing something about it NOW, instead of waiting for the next miracle gas saving technology or device.

    I just do not see it on the interstates around here. I dont think the general population gives a damn, except to bitch and moan at the gas pump.

  • avatar

    First off, all of you who think super + turbo technology is new, go read up on the Nissan March Superturbo. I’m sure VW has refined it (besides, the March Superturbo was performance oriented), but it’s not new.

    Secondly, I think it’s far too early to count out diesel. There are improvements to the classic Otto engine, but some of these improvements apply to diesel as well and it’s not like diesel technology will stand still. It’s a very daring statement to claim a technology is mature or at a dead end, and nothing I see shows that for diesel. Continued investment in diesel tech will reap rewards of cleaner and more powerful diesel engines.

    I think a better argument would be that hybrid tech will kill non-hybrid tech and we’ll see a mix of gas and diesel hybrids.

  • avatar
    Paul Niedermeyer


    I’m not calling the diesel dead by a long shot. I’m just pointing out that some interesting alternatives are developing, and that diesel market share will settle back closer to what it was historically.

  • avatar
    Glenn 126

    Right on jerseydevil. After I got stopped by the local county mounties for going 5 over the speed limit about 6 or 7 years ago (you know, the old “random involuntary tax revenue generation” trick) I said – hmmmm, I can’t afford to give these pinheads any of my hard earned money (since I live in an area paid 1/2 what people make downstate, and the cost of living is already higher than the rest of Michigan – including gas).

    So I said – FINE – I can drive the speed limit. So I and about 0.0001112345% of the rest of the population do so.

    You’ve never seen so many p*ssed off people in your life. Actually, you’re right – my opinion exactly. They can tailgate and endanger my life but they can’t intimidate my cruise control – set at the speed limit (in the right lane).

    Of course the imbiciles can’t be bothered to actually pass. They sit 3-4 feet off my rear bumper (apparently just to prove what total pr*cks they are?)

    Actually Michigan drivers suck so badly that they were tailgating me all the time when I went 5 over so what’s the difference?

  • avatar
    Jan Andersson

    Hello, Uncle Sam! You are pleased with the power and torque from your present car’s gas engine, right? Well, when you are sleeping tonight, we’re going to replace it with a new high-tech European diesel engine! We’re also going to leave the radio on high volume so you won’t notice the changed noise. So when you drive off, you’re not going to notice any changes at all, because of the automatic tranny. But now you have an engine half the size of your old, which will consume half the fuel amount for the same driving. No bad deal, eh? We’ll send you the bill later, and you will pay it with a smile.

  • avatar

    gosh! diesel is an imitation of an engine. the europe is overloaded with these unbelievabele shattterboxes. whenever there is even the high-end 7-series or merc s-klass sitting and idling at an intersection, waiting for the green lights to release the devilous sulfur clouds like some hiding giant squid, you can hear the tremors like from a parkinson desease sending vibrations all around the hood. diesels stink. I mean it literally. but it doesn`t stop europeans to buy them. they sit in a 100k merc or audi and the engine sounds like some yugo zastava nightmare from yugoslavia, but they still want to save a couple of cents on a mile. would you really care for a mileage if you could afford a 100k merc? diesles are better for trucks, because they need big torque at low rpm starting to pull a cargo ,or crawling uphill. diesels are so much overloaded today with back-up shit, and insulation, seems like germans have desperately been looking to make the diesel alive. people say diesles are today as powerful as fuel engines. alrighty then …. let`s not compare turboed diesles versus naturally asprated fuel engines. let`s compare both in turbo versions. ooops! show me a non turbo diesel that would crank out as much as ,say, toyota`s 1.8 liter 192 hp fuel engine? well, you save gas at pump with diesel? how bout comparing similar output engines , not similar displacement engines, for customer doesn`t see or feel a displacement , but output and gas consumption is tangible. here we go, a 2 liter diesle is comparable to 1.6 liter fuel engine. dielse has more torque? try accelerating to 200km/h and see where is your diesle then… i can`t understand why do you have to improve an old shoddy diesel technology if fuel engines have proved themselves worthy? national pride of germany? well, then don`t send your second hand national pride crap to my country. we don`t need your sulfur/co2 residues and the tractor like engine work. please…..

  • avatar

    You need to be less myopic and look at the big picture. The first thing is about the post above…didn’t you hear…diesels have won the last two 24 hour of LeMans races. A diesel hybrid will out perform a gas hybrid in mileage AND get less polution per mile. The estimates need to change to per mile instead of per gallon to get a true picture of CO2 and NOx. I could start throwing out stuff like…There is now more PM coming off your four tires that from a newer diesel. True or not, the point is to get the best overall result for our future. To refer back to the old days in the USA of the “diesel” cars and compare them to the new diesels is ignorant. Gas nor Diesel cars now are nowhere near the cars of the 70′ and 80’s.  The statement that gas engine put out less CO2 that a comparable diesel is just wrong. Also with the newer ULSD, PM have decreased and would most likely be gone if EGR systems were trashed and NOx traps were perfected. PM is formed BECAUSE the diesels are under strict PM mandates. The bottom line is that fuel usage and pollution is going to be an ongoing struggle to control. We would do better to control the population and decrease the “user base”. Gas or Diesel, rate them based on a MPG scale rather than giving a “clean burning SUV” that gets 14mpg codos when a VW Diesel getting at least 3 times that MPG puts out LESS pollutants over a 300 mile trip than the “Clean SUV”. You also have to factor in the fuel/pollution it takes to transport the fuel to the customer ect.

  • avatar

    Correstion above…PM is formed BECAUSE the diesels are under strict NOx mandates. The EGRs that are used to lower cylinder temps to limit NOx, cause an increase in PM.

  • avatar

    Regardless of the physics, I view the diesel vs. gas issue in terms of commercial applications. Where are these engines used commercially, because that is where the economic rationalization occurs?

    Trucks that transport cargo for a fee tend to be all diesel, guess it pays to use diesel for that purpose.
    Cars used to move people and things tend to be mostly gas, guess it makes sense economically to use gas for that purpose. Example, taxis in big cities. I know in Europe they use diesels for taxis, but then that may be more a function of the way they tax fuels there.

    I once knew someone that claimed it was more economical to drive a diesel Mercedes. When we did the calculations we concluded that it was actually less expensive to drive a Chevrolet Impala using gas and this was replacing the Chevrolet every five years to the Mercedes 10 year life. This was in the 1980’s so some things have changed, but not all that much.

    Regarding the CO2 emissions. Plants love and need CO2, we might ought to consider planting more to balance our C02 creation.

    Happy Independence Day and let us remember that we have choices because of the principles established by the brilliant founders of these United States.

  • avatar

    This has been one of the more enlightened discussions about fuels, engine technologies, fuel economy, and emissions.

    Here is a set of databases that I have found of value for comparing various vehicle manufactures and their products regarding makes/models, fuel economy, and emissions.

    One of the most easily accessed and understood is UK’s VCA database. Here is a listing of vehicles achieving 120 g/km CO2. Interestingly these 36 vehicles get over 47 mpg(US) combined city/highway … ~22% are from , Ford, Vauxhall (Opel/GM), and Mini Cooper D. Another ~20% come from Honda, Hyundai, Toyota, and VW. Diesels make up 25 of the 36 vehicles. Where do you think those advanced gasoline engines are (either emissions or fuel economy)?

    Here is a way to see all make/models

    Or, here you can search by mpg(Imperial) … you can convert to US gallon by dividing by 6 and then multiply by 5.
    Oh … you can sort CO2 values ascending or descending. You can also check NOx on the model detail data sheet.

    FORD has a number of interesting vehicles. Check out the Mondeo (including the Estate), or the Tourneo Escape (including the 9 passenger version). If you want somehing a little smaller see the Fusion or the Focus.

    The 2007 Mondeo is the quietest diesel I have found so far. It is a Duratorq. This diesel engine ranges in size from 1.4 to 2.2 liter … my memory.

    Unfortunately … WE NEED AT LEAST 40 mpg(US) … NOW !!

    Maybe Congress should waive ALL import restrictions and tariffs on all vehicles meeting 44 mpg(US) or better and Euro Step IV emissions and EU Safety standards [ or their rquivalent] for 36 months (or, if by quantity, 400,000 units of any model that satisfies the criteria).

    Let’s see what the consumer will do with REAL differientiated choices!

  • avatar

    “diesels stink. I mean it literally. but it doesn`t stop europeans to buy them.”

    The trucks in Europe exhaust from underneath which adds to the stinky and grimy problem. In the US, trucks exhaust from a stack over the cab.
    There is a lot of grimy soot everywhere in Germany from diesels.

  • avatar

    Great article.

    Diesel technology is not standing still, but the fact remains that diesel tech is more mature than gasoline engine tech.

    Diesels are practically a necessity in towing or moving heavy loads. Diesels in that segment will always remain and improve.

    Toyota and Hino are both developing next-gen small and large diesel engines in partnership with Isuzu, as is Honda. Toyota ultimately believes in hybrid technology though.

    There are plenty of improvements left for gasoline engines which would not do anything for advancing diesels. direct injection and variable valve lift (eliminating the need for a throttle body) can increase power as well as fuel efficiency in gasoline engines. There are also developments such as fully electric variable valve timing that will further help improve gasoline engine efficiency.

    The main point here is that gasoline engine development is moving along at a faster pace than diesel engine development.

  • avatar

    it’s great to read such an informative debate. a few contributors have brought up gasification from coal. it is also possible to convert natural gas to liguid. qatar has a huge refinery for doing just that. i believe that it runs in diesel engines without modification. i rented an lng based hyundai sonata when i was in korea. i think it had a conventional internal combustion engine that had been modified to run on lng. the car performed exactly like a conventional car. in fact, i had no idea that it ran on lng until i was at the pump. i realize that the economics of this stuff probably doesn’t work in the so called free market but we should look at some of the advantages:

    1) it burns very clean even in diesel engines

    2) north america has an abundant supply of natural gas

  • avatar

    Glenn, you said… I understand the Prius taxicabs in use (most of which are in Canada – tough conditions!) last 250,000 miles before being replaced I think you'll find that most of those Canadian Prius taxicabs are here in Vancouver, where the conditions are far from tough – it's pretty warm and wet and typically we get only a couple of days of snow a year. But there's no doubt the 2004+ Prius is hugely popular with the local cabbies, and those guys normally have a pretty good handle on a vehicle's economics.

  • avatar

    Boy, I really see that this article was not to spill the truth about diesels but to just make people buy more gasoline from saudi arabia. Why should we remember last hangover from 80’s? The diesels of today are a lot cleaner than a lot of gasoline cars. And it’s not fair to compare diesel cars to hybrids, because hybrids are just piggyback systems of gasoline cars. A fair comparison is diesel to gasoline, because hybrid is not a standalone energy source. I never knew that making Prius bareties was so environmentally friendly when they have to be disposed. Of course diesels emit more CO2 because they have more energy per btu than gasoline. Overall efficiency wise, diesel is more efficient in every aspect except NOx. Man what a complicated urea-treatment system. It’s literally another catalytic converter that you don’t have to do any maintenence on. The author probably doesn’t know that common rail diesels are supposed to be t2b5 compliant and they are the current peak of diesel technology. Remember Bosch is making all the injector systems, and they are setting their production lines to have more diesel orders than gasoline orders by 2010. This author needs to get his facts straight. BTW, i don’t drive a diesel but am waiting for new line of them as they just make more sense.

  • avatar
    Paul Niedermeyer

    kudos328: My facts are quite straight. I specifically do compare gas to diesels (the three VW engines). The main focus of this article is not diesel vs. hybrids, but that gas engines are enjoying new technologies to make them more competitive (in fuel consumption) to diesels.

    “the author doesn’t know that common rail diesels are supposed to be t2b5 compliant…” They aren’t, per se. Common rail diesel injection has been around for almost 15 years, and they don’t make diesels t2b5 compliant. It takes NOX cats and/or urea injection along with particle filters achieve t2b5. That all adds a lot of cost; t2b5 compliant diesels will be as or more expensive (compared to straight gas engines) as Toyota’s full hybrids are.

  • avatar

    Hmmm, lots of diesel misguidance on here. Obviously many have succumbed to the false rambles of idiots who think they know about the car industry.

    IMHO diesel are the answer. Modern properly controlled and tuned diesel do not smoke at all unless under a heavy load. Cold rough starts are a thing of the past and I like the clatter of a good diesel. I cant start both my diesel at below zero °F with out block heaters, the chevette is a little groggy, the duramax starts on the first crank.

    Diesel technology has come a long way. Diesel emissions technology is still fairly new with plenty of room for improvement. In the short term there is no reason to be concerned about NOx emissions, everyone would have to switch to diesel over night for it to have an impact.

    Thermodynamically, diesels are roughly 30% more efficient at converting chemical energy to mechanical energy. Thats hard to ignore. Thats a 30% gain in efficiency out of the gate, without a whole bunch or expensive heavy technology and environmentally unfriendly batteries.

    To say a prius can obtain better mileage than a modern diesel is a flat out lie, the proof being that diesel cars were getting prius like mileage 20+ years ago. Things have only become better since then.

    That article is interesting, it starts by knocking GM for its late 70s – mid 80s diesels, proof to existing prejudice right off the bat, the article then later mentions how you can practically breath a hybrids exhaust, I say have at it, why don’t you prius owners route your prius exhaust into the cab. I want to see if that theory stands.

    Also a modern diesel car will surpass the most advanced hybrid on the market in mileage. Couple the fact the diesels are more efficient, it takes significantly less energy to refine diesel as opposed to gasoline, and diesel are flexible in the fuel they can burn, its really a no brainer. Diesel are clearly better than hybrids.

    All we need now are some new modern domestic diesel cars and we would be in business.

  • avatar

    Finally someone lets out the basically understood, but largely voluntarily ignored facts about the many, many detrimental effects of diesel engines. Good article.

  • avatar

    I find the diesel discussion to be more than slightly reminiscent of the usual discussion about the Big 2 Point Whatever — a relentless clash between ideology and market reality.

    The American marketplace has spoken loudly and clearly on this issue — it just doesn’t want diesels. They don’t sell well, they’ve never sold well and there’s no reason to believe that this situation is going to change.

    I’d like to hear a cogent argument as to why anyone expects the marketplace to suddenly undergo some sort of epiphany that has escaped it for well over a century. If it hasn’t happened already, it’s tough to believe that anything is going to be radically different anytime soon. Every time that the market has voted, the oil burners have lost the election, by a landslide.

  • avatar

    Quite to the contrary, I think you have your head in the sand. If the big three and the import makers offered diesels in their consumer car line-up they will sell quite well.

    And also there are no more detrimental effect of diesel as their are to gassers. Only old thinking ans ignorance would support that.

  • avatar

    If the big three and the import makers offered diesels in their consumer car line-up they will sell quite well.

    You might want to stop and consider the blatant reality, er, possibility that they don’t offer these cars because there is no demand for them.

    It should be evident by their success that Honda and Toyota are not run by buffoons. These companies clearly understand the tastes of the American buying public, and their commitment to diesel is minimal. If they thought that it would be as profitable as you claim, then they would have already jumped in with both feet a long, long time ago.

    Diesel has never, over the last century, been anything more than a niche product in American cars. The fuel tax regime in the US has never given the favorable treatment to diesel as it has in much of Europe, so the US provides a good example of what happens when market forces drive consumer choice. As a result, the only makers that have pushed diesel cars in the US are European makers that have an incentive to sell a few more units abroad of what they’re already building for their own home market.

    Like GM’s endless recovery plans that never come to fruition, this is yet another one of those “manana” stories — tomorrow is always supposed to be different from today, but never is. When tomorrow arrives and becomes today, what was supposed to have happened never does, and so it gets pushed off until the next day or into next week. It’s the proverbial carrot at the end of a stick that the horse tries to catch, but never does.

    If diesel hits 10% market share in the US, I’d be surprised. It’s currently at 3%, and nobody in the industry is predicting substantial gains. If there is any company in the market with an incentive to make it pay off, it’s Mercedes, yet even they are keeping their expectations at about the 10% level.

    You may be enthusiastic, but aside from the occasional poster on the internet, not many other people care. Let’s not confuse the tastes of a few people cooking veg oil in their backyards with the views of the typical consumer.

  • avatar

    Pch101: “The American marketplace has spoken loudly and clearly on this issue — it just doesn’t want diesels. They don’t sell well, they’ve never sold well and there’s no reason to believe that this situation is going to change.”

    What are the choices in the US for diesel … the majority are over 4 liters with the exception of the VW offering expected in 2008 … and maybe the Jeep. The majority of domestic diesel engine offerings are about the size of a 1970s vintage tractor trailer engine (I don’t need the ability to pull 40 tons). Granted Mercede BlueTec does the job BUT it is out of my price range.

    Your statement that “They don’t sell well” is because they were NEVER AVAILABLE to be purchased and the “rules are rigged” to prevent import!

    Waive import restrictions on vehicles getting better than 44 mpg(US) combined city/highway and see what happens to the market. That would place the engine size in the 2 liter and below range.

    I think it would be a safe bet that within 5 years at least 30% of ALL NEW SALES would be diesel OR diesel hybrid. In fact, IF the pricing is reasonable and the quality and durability are demontrated to be high, the sales could easily exceed 50% within 5 years … just like what happened in the EU.

    Before you say I am wrong … check the information available at
    then we can discuss it.

  • avatar

    You’re right that Honda is not run by buffoons. As proof, Honda is dropping the hybrid Accord in the USA and replacing it with a diesel Accord that will get better mileage. They have also find a way to scrub the NOx without the urea additive.

  • avatar

    Here is a link to Honda Diesel…Impressive!
    Don’t know how much energy is extracted from the system, but we will soon find out.

  • avatar

    Your statement that “They don’t sell well” is because they were NEVER AVAILABLE to be purchased and the “rules are rigged” to prevent import!

    Here’s a basic rule of thumb for you: If a conspiracy theory is required to support your ideas, chances are high that your ideas have some serious flaws.

    This is the world of automotive marketing, not the Bermuda Triangle. If there was so much pent up demand for diesel, these guys would have been all over it, with the production to match.

    It’s not Hollywood, either, and as fans of the Big Two Point Whatever have finally discovered, this is not Field of Dreams. You can build it all day long on triple shifts, but if the output doesn’t serve the tastes of the public, then they just aren’t going to come. Supply does not create demand; it’s demand that motivates producers to supply it.

    I think it would be a safe bet that within 5 years at least 30% of ALL NEW SALES would be diesel OR diesel hybrid.

    There isn’t a single credible automotive industry analyst or industry insider who believes this. The only people who believe this are the die hard diesel fans who have predicted such glorious success since dinosaurs roamed the earth. The sober experts have no such expectations.

    In 2012, I’m sure that the diesel cheerleaders will be telling us that this market surge will be with us by 2017, and in 2017, it will be delayed until 2022. It’s always tomorrow, but never today.

    As proof, Honda is dropping the hybrid Accord in the USA and replacing it with a diesel Accord that will get better mileage.

    Not all hybrids are created equal, and Honda’s methodology behind its particular approach has not resonated with the public, while Toyota’s clearly has.

    Since Honda is offering diesels in Europe, where the fuel taxes motivate consumers to buy them, and since Honda can’t compete on Toyota’s turf, it can’t hurt to try to sell a few diesels.

    Selling a few does not equate to selling a lot. JD Power is predicting that diesel will hit 7.5% market share by 2012. The fact that 92.5% of the market is expected to stay with the status quo tells you that in the boardrooms of industry, hopes for diesel are not all that high. It’s a specialty niche product, not the wave of the future.

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    Pch101: The reason that you didn’t see high sales in 07 in diesels was because emissions regulations prevented cars from passing the tests. Sure we want cleaner stuff and we always get more efficient cars vs. more performance cars. In canada half of new vw were diesels, and there is a high demand for A4 (97-04) platform diesels because there were none in 07. If you try to find a diesel used car, you will find them to be just as expensive as like 2 years ago. This is because these cars are becoming more and more rare, and people do want them. Sure it’s a niche market, and there will always be the american public that want to drive their suburban to work everyday all 8 miles in bumper to bumper traffic. You can’t appease the idiot public. For those of us who want to make a difference and even save money on our commute then diesel is the answer. And biodiesel makes a lot more sense than hybrid, as using waste for fuel gives us more fuel and it will last longer. /end rant

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    The reason that you didn’t see high sales in 07 in diesels was because emissions regulations prevented cars from passing the tests.

    Well, that sure explains the last hundred years of relative failure. The inability of diesel to crack the US market is not a new phenomenon.

    You can’t appease the idiot public.

    Here’s another theory for you: If your beliefs are built on the premise that everyone who doesn’t agree with you is an idiot, then you need to go back to the drawing board and grab a mirror.

    The public votes with its dollars, and it just isn’t voting with you. Year after year, millions of people shun your ideas in favor of something different.

    The automakers need to serve the public, not a few fans who aren’t sufficient in number to pay the bills. Toyota is selling more Priuses to Americans than VW is selling Jettas of **all** types, both gas and diesel, while overall Jetta sales are in turn just a small fraction of the Accord, Camry and Altima. It’s a niche, and a small one at that.

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    I agree that Toyota shouldn’t change their product line to fill a niche void, they already do that with the hybrid. I just wish people would be given a choice to have diesels as they are in my opinion a better choice, as well as the fuel is cheaper, at least where I live.
    I do agree that Jettas do have lower sales than the Japanese cars because well German cars cost more and people get turned off by that. Surprisingly, they don’t get turned off by Suburbans that get 18 mpg. That’s the idiot public i’m talking about. I’m not saying that everyone who doesn’t agree with me is an idiot, but there are a lot of people who drive a vehicle that is not made for those purposes, as i mentioned, a suburban driven by 1 person to get to work sitting in bumper to bumper traffic. Ask me how i know.

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    PCH, if you believe your assumption is correct that no one will buy turbo diesels under 2 liters, then you should support the waiver on import ristriction on 44 mpg(US) vehicle … IF for no other reason than to prove that US “fools” are wrong.

    On the other hand IF you can’t support the waiver … you must have some strong doubts about your position and maybe even fear that the waiver will errode Det3 sales even further.

    Which is it?

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    PCH, if you believe your assumption is correct that no one will buy turbo diesels under 2 liters, then you should support the waiver on import ristriction on 44 mpg(US) vehicle

    My personal opinion is irrelevant, and trying to convince me of the genius of diesel misses the point.

    Rather, the fundamental issue here is that the market has spoken, and it has said “no” to your dream of diesels. Your war on alleged import restrictions isn’t going to change a thing about the market’s opinions about the technology.

    If you want to appeal to the market place, then you need to offer a more compelling value proposition — obviously, it just isn’t compelling enough for very many people to switch. Legislation and internet debates are not a cure-all for a lack of demand.

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    PCH I believe if you are honest about diesels in the US … you will recognize that the “marketeers” have decided the “demand” not the consumer.

    It will be interesting to see what happens when the new VW diesels arrive within the next 12 months.

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    I believe if you are honest about diesels in the US … you will recognize that the “marketeers” have decided the “demand” not the consumer.

    Er, no. Consumers are perfectly capable of determining what they want and don’t want, and they have decided against diesels.

    Just because they don’t agree with you does not mean that they are crazed lunatics hypnotized by Madison Avenue. They don’t demand it, so companies don’t provide it. I’d keep the conspiracy theories where they belong, i.e. at the bottom of the dumpster.

    Companies sell products in order to make money and build market share. If money and market share could be created through high volumes of diesel sales, then of course they would be doing it. But consumers don’t want it, so they don’t bother. Demand drives supply, not the other way around.

    It will be interesting to see what happens when the new VW diesels arrive within the next 12 months.

    It will be the same as before — not much. VW is a tiny niche player, largely unpopular with the American consumer. (For the record, I like VW’s, but the average consumer disagrees with me, too. No, I’m not offended…)

    Toyota retailed more Prius cars in the US during the first half of the 2007 model year than VW sold Jettas, Rabbits and New Beetles combined. The marketplace is very clear in what it is saying, you just don’t want to hear it…

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    There is a segment of the American population that will jump on hybrids just because they get more mpg. Despite the up front cost penalty and unknown long-term costs. I believe this same segment (and many others) would jump on diesels if they were offered on a low-to-mid priced car that was within reach of the average person. But there would also have to be some good marketing to sell the diesel concept to these folks. They still view diesel as dirty and smelly because they still see and smell the big rigs, delivery trucks and other heavy duty diesels. They don’t realize that diesel passenger automobiles are neither heard nor smelled anymore. Once the word is out and people start seeing the early adopters buying clean diesels, I believe the tide will turn away from hybrids.

    Right now, Mercedes can’t build enough diesels to satisfy the demand. High end buyers recognize the advantages; it isn’t just about fuel cost savings. If these buyers can afford the 3-pointed star, they can certainly afford to buy Premium gas. Sure, everyone likes to save a few bucks at the pump. But the demand is outstripping the supply of MB diesels because of the overall advantages of diesel technology.

    This has been a good discussion. Nobody will convince the purists on either side. But the vast American population in the middle deserves choices, and diesel is a smart choice for many people. They just need to have that option on a low-to-mid priced car that they can afford.

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    Pch … please explain how the American consumers “CHOSE” not to buy a small turbo diesel (under 2.2 liter) in the last 3 years. Wasn’t the VW (“largely unpopular with the American consumer”) the only offering and it’s diesel has been unavailble for the last 12 months or so?

    So what was the choice for the consumer to make?

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    There is a segment of the American population that will jump on hybrids just because they get more mpg. Despite the up front cost penalty and unknown long-term costs. I believe this same segment (and many others) would jump on diesels if they were offered on a low-to-mid priced car that was within reach of the average person. The appeal of the hybrid to its initial customer base was not its fuel economy, but the whiz-bang technology that it deployed and “green” aspects of the product. The fact that it was new technology that was distinctly different from the conventional car made it much more interesting to the early buyers. That, and it’s the electric motor. Hybrid buyers are not attracted to the gas motor, but to the electric one. You make the mistake typical of those who don’t understand its success — you are viewing it as a gas powered car with a big battery, whereas the hybrid buyer views it as an electric car without the range limitations of a conventional electric. That, and unlike diesels, which will evolve slowly at best, hybrids will be improving significantly, with the next generation expected to be vastly more efficient than the current one. These changes will move hybrid fuel economy from being on par with diesels to being substantially better. The next generation of the Prius is slated to get 80 mpg (US), a level far better than any comparable diesel could ever hope to get. The segment of the market attracted primarily by fuel economy will be going hybrid, not diesel. please explain how the American consumers “CHOSE” not to buy a small turbo diesel (under 2.2 liter) in the last 3 years. It’s not just three years, it’s the last century. Diesels have never been popular with American consumers, not ever. You keep pretending that there is a conspiracy that doesn’t exist. If companies thought that they could sell diesels in large volumes, they’d be building them — why would they pass up on such easy money? You don’t see diesels for the same reasons that you don’t find many stables and buggy whips being sold in your area — people don’t want them. You don’t make a profit if you build stuff that people don’t buy, so they don’t build them in large numbers. If there was such demand, companies would be lined up around the block trying to fill it. For you to be correct, you’d have to honestly believe that all of the automakers are idiots, and that you possess unique insights that is not had by any automaker operating in the US today. Even the Mother of All Diesel Builders, Daimler, is not betting big on US sales. Do you really believe that you are more knowledgeable about market demand for diesels than they are? 

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    Don’t kid yourself. Most people don’t buy hybrids for the “whiz-bang technology”. They buy them to get better fuel economy and to affirm their green credentials. Too bad they don’t know about strip mining for Nickel batteries and disposal issues for those same batteries years later. Like ethanol, hybrids are a green illusion.

    And I’ll believe 80 mpg when I see it. Downhill at 10 mph with a stiff tailwind doesn’t count.

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    Pch .. Are you saying that you would reject the 70 mpg(US) combined average PSA/Cittoen/Peugeot hyibrid electric expected by 2009 as a “plug-in capable”… because it has a diesel engine with CO2 emissions expected in the range of 90 g/km?

    As for your comments about 100 years of experience with diesels in the USA … with the exception of a few years in the 70s and 80s the “domestic” diesel experience has been limited to “truck” engines with the exception of MB and VW plus a few others.

    There have been significant changes in diesel technology world wide since 2000. Fot example can you name one “domestic” production diesel that “Red lines” above 5,000 RPM? How about 4,000 RPM? 3,500 RPM?

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    Are you saying that you would reject the 70 mpg(US) combined average PSA/Cittoen/Peugeot hyibrid electric expected by 2009 as a “plug-in capable”…

    The problem with this discussion is that you are trying to center it around me, when my personal tastes and whims have nothing to do with the topic.

    The issue at hand is how the American consumer would change his ways in order to make your diesel dreams be realized.

    The size of the US new light vehicle market (this includes both cars and light-duty trucks) is roughly 16 million new vehicles sold each year. Of these, diesel has about 3% market share, or about 500,000 units, including pickup trucks.

    Based upon these numbers, in order to increase market share in 10% increments,you would need to increase sales by roughly 1.6 million diesels each year; 1% increments would equate to about 160,000 vehicles.

    Now, let’s pretend that it is your job to develop a plan to change this. You need to turn the 3% market share figure into the 30% that you predicted above. This would require increasing sales by about 4.3 million units per year.

    The question becomes: How exactly are you going to achieve this? Let’s digest what 4.3 million units looks like on the automotive horizon —

    -This is approximately 10 times higher than VW and Mercedes combined total annual US sales, including both gas and diesel cars

    -This is about 10 times higher than total US sales of the Toyota Camry

    -This is about 12 times higher than total US sales of the Honda Accord

    -This is about 16 times higher than total US sales of the Toyota Corolla

    For comparison’s sake, here are real-world sales figures: VW sold 29,000 diesels in the US during 2005, while Mercedes sold about 5,000 E320 CDi’s during the same period. These are the leaders in the business, yet even they can’t sell very many. That’s 34,000 cars. You need 4.3 million. Where exactly are they going to come from?

    This segues to the critical queston: Who is going to buy them? You now have to convince 4.3 million car buyers to change their minds. How do you intend to do this, and what indications are in the current market that hint that such a change is possible, when the market leaders already can’t even come close?

    These are not rhetorical questions. I’d like to see a realistic plan of how achieving this would be even remotely possible.

    When J.D. Power predicts that diesel share will increase from 3% to 7.5% through 2012, they have good reason for being far less upbeat than you are. They have crunched the numbers and figured out that 4.3 million units in the US car market is a very steep hill to climb, for anyone.

    These lofty projections of diesel success look about as likely as a housefly swallowing an alligator. Hitting high targets would require a massive change in consumer tastes, plus dramatic shifts in the product mixes of virtually every automaker doing business in the US. Nobody in the industry sees this being even remotely possible, including companies such as Bosch that have a vested interest in supporting diesel expansion.

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    “I’d like to see a realistic plan of how achieving this would be even remotely possible.”

    A TV Commercial:

    Ugly dude in a Jetta diesel stops at a light next to a car full of hot babes. Babes suddenly want to have sex with ugly dude when they discover his engine is a diesel.

    I think a good marketing test will be when Honda brings their Accord diesel to market in MY2009.

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    I think IF I were Ford and GM I would approach Congress to request a 3 year waiver of import restrictions and tariffs on diesels getting over 40 mpg(US) combined average. That would give “my” industry 3 years to resolve emissions and safety issues necessary to meet domestic standards.

    Ford has an excellent array of diesels from mini busses (similar to the Sprinter), Escapes, SUV, mid size sedans and station wagons, down to small cars. GM (Vauxhall/Opel) has a reasonable collection also. Chrysler seems to be in the weakest position in this arena.

    As to market penetration, one has to assume that supply matches demand which it probably won’t. Like in 1975, with the introduction of the Honda Civic CVCC there was a 100% premium over POE demanded by many dealers.

    That said … if sales start at about 100k units the first year with reasonable pricing (in the range of $20,000) and good delivered quality, then it is reasonable to expect annual volume doubling. At that rate, within seven (7) years approximetely 40% of new sales could be diesel. Keep in mind that there are many people out there (both civilian and military) that have already experienced the EU diesels in their travels and are frustrated by the diesel absence in the US market.

    At this point the only competition in mpg are a few hybrids (only 2 at this time). However there will be diesel hybrids within the next 4 years … whether available in the US or not.

    There are three (3) things that might change that rate of penetration: 1) gasoline vehicles getting 50 mpg (not likely); 2) A new breakthrough propulsion technology (not likely); 3) fuel prices over $5/gallon (very likely).

    If I do “IT RIGHT”, customer “satisfaction” will establish a customer base that will sell the vehicles for me. In other words, the new satisfied owners will do the advertising for me because they will be saving between $1,200 and $3,500 in fuel cost for the average driver and IF their expectations are met … they will “brag”.

  • avatar

    I think Luther and himpg both have it right.

    Prime the pump and create initial demand by advertising it with “image” ads. Use targeted product placements in movies, ensure that the blogs are buzzing, target younger people and generally appeal to the Early Adopters. Ensure that the product is absolutely golden at launch, sell a bunch of them, coddle the initial owners and make them feel so special that they tell all their friends (the brag factor…as himpg stated) and let the early customers fuel the frenzy so people without diesels feel left out.

    I’m no fan of GM, but they did their Saturn launch right. Saturn had a cult-like following. An aura of something special. Use that as a template. But, unlike GM, don’t drop the ball once you’ve got some momentum.

    In short, it’s all about quality engineering and very clever marketing, followed by word-of-mouth from satisfied customers.

  • avatar

    Prime the pump and create initial demand by advertising it with “image” ads.

    Diesel has a negative image among the American public. A few ads won’t cut it — ask GM whether a few glossy ads are sufficient to turn their fortunes. They aren’t.

    I think IF I were Ford and GM I would approach Congress to request a 3 year waiver of import restrictions and tariffs on diesels getting over 40 mpg(US) combined average.

    OK, that is not going to happen, so drop that line of thinking. And even if it did, that would not fix the primary problem, which is the lack of demand.

    I listed some statistics in the hope of giving you a sense of perspective. Let’s look at what some of those mean:

    -It took Honda more than three decades to hit Accord sales that are at 1/12th of your target. And that’s marketing a desirable product that actually meets customer needs and that didn’t begin with an image problem.

    -Mercedes sells 5,000 E-class diesels in the US each year. This is coming from the spiritual leader of the entire US diesel business, and they can’t even hit a tiny fraction of one percent of your goal. Ask yourself why that is, and whether anyone can possibly claim that a car that sells 5,000 units per year is “hot” when that equates to about ten days of Prius sales.

    Speaking of the Prius, it is considered by those in the automotive business to be a wildly successful hit in the US. The buzz is so incredibly good that any automotive marketer would kill to have it. The Prius will have a banner year this year — sales in 2007 will about double 2006 sales — with Toyota reasonably projecting that US sales will hit 175,000 units this year.

    Think about it. With Toyota firing on all cylinders and doing everything right, with market conditions lining up in a way that couldn’t have been better for this product, and without any negative image to overcome, it has nonetheless taken them eight years to hit 175,000 units, a figure that is a mere **four percent** of your target. They do everything right AND get incredibly lucky, and yet even they aren’t anywhere close to the target that you’ve set for a product that many Americans are inclined to avoid.

    Your goal is just not going to happen. Nobody in the business believes it will happen, precisely because of the market realities that I have just outlined above. Nobody is expecting to take a technology that people dislike, and to completely transform their perceptions about it while disrupting their successful product mixes to do it. Accomplishing this feat would require them to hit sales records that are without precedent. Just grab a calculator and review the market data, and it’s clear that it comes nowhere close to supporting your aspirations.

  • avatar

    “In 1989, VW/Audi ushered in the modern direct-injection (TDI) diesel.”

    VW didn’t invent the idea of turbo direct injection diesel engines in cars, that was done around 4-5 years earlier by now defunct Rover group – which then unfortunately failed to invest in it and bought quieter units from Peugeot. Yes, these were the same guys who didn’t invest in MGs and withdrew from the us.

    There were probably others with Di engines in cars before then too.

    “The group’s oil burning powerplant set a high-water mark in the diesel’s long development….While the diesel’s efficiency peaked in 1989…”

    I would suggest the evidence is to the contrary.

    The original TDi engine had 90hp from 1.9 litres, made 50 mpg. It was one of the earliest direct injection engines but it was essentially hampered by previous generation technology surrounding it. The MPG figure was better than the competition but the power was nothing special.

    In the 90s the TDi engine got the high pressure PD fuel injection system, common rail and all sorts of emission control trickery. It went from 90hp to 110, 130 and eventually 150hp whilst economy remained largely unaffected. It also got quieter. A lot quieter after the electronic FI system replaced the old noisy mechanical fuel pump – the thing that makes all that clattering noise.

    As a contrast PSA have had a 1.4 litre HDi engine which makes 90hp for 4-5 years, thats the same from 1/2 a litre less. They also have a 1.6 litre unit which generates 110hp. Even the Koreans (Kia) make a 1.5 litre unit which delivers 100hp/50+ MPG and is very smooth.

    The new VW engines go even better. Want economy ? The new TDi PD 1.9 litre makes 105hp and close to 55-60 mpg. Power ? The 2.0 makes 140 as standard, or 170hp if you prefer, mid 40s MPG.

    “With the diesel’s efficiency superiority down to 25 percent, a “clean” diesel emits only 13 percent less CO2 than yesterday’s gas engine. And that small gap is… wait… gone.”

    Well only if we accept that high water mark again, and if Diesel technology will stand conveniently still and if Petrol continues to improve. Thats a lot of ifs.

    “A CO2 output comparison with two other similar-output VW engines is telling. Their 170 horse 1.4-liter TSI produces 174g/kms of CO2. … And their 170hp 2.0-liter TDI diesel (not US compliant) produces 160g/km.”

    This is telling me that the TDI 170 emits less CO2 from 2 litres than a 1.4 litre Petrol unit. I have no idea what the old boat anchor 2.5 is doing in the US golf, maybe VW have realised how little they need the US market.

    “With diesel-like torque and direct injection, it’s the best of both worlds”

    The 170 TDI makes 256 lb./ft of torque, the TSI makes 177 lb/ft. I know which one I would want to be overtaking in.

    “A study by the consulting firm AT Kearny confirms the diesel’s demise.”

    No it doesn’t – there is a difference between predicting and confirming something as you yourself go on to say:”

    “It predicts that only 25 percent of Europeans will find diesels an attractive economic proposition by 2020.”

    Fuel costs in Europe run 3-5 times higher than the US. Diesel may get replaced probably by whatever replaces petrol as well. Whether thats gas, electric, flux-convertor, who knows.

    “Although Rudolf Diesel’s engine WAS intrinsically more efficient, it turns out that Otto’s engine is a lot more clever at learning new tricks.”

    I’m pretty sure the truck industry may take some issue with that. However new tricks, old rules. Keith Duckworth (the “worth” in “Cosworth”) said “The power output of an engine [equals] the size of the bangs, times the number of bangs per minute that you can manage to get.”

    Its a simple idea and one which neither engine can get round.

    All the TSI does is to work with it. Forcing more air in to which more fuel can be added resulting in a bigger bang. Unfortunately other factors – 2-3x compression ratio in Diesels, much leaner mixture, longer stroke and more energy in the same volume of Diesel still create a mountain of development to enable Petrol engines to match it.

    The TSI is a brilliant idea. Perhaps a revolutionary one in a road car although Lancia came up with the combination first in the 80s in their Delta S4 rally car.

    But to suggest it heralds the end of Diesel I think is premature at best.

    So why are the Europeans rushing to make Hybrids ? Well, thats for the same reason that the Japanese rushed to get Diesel engines into their European cars as quickly as possible in the 90s – you can argue against it or you can make money off the back of a market someone else has created.

    Which would you choose ?

    Its worth noting that most of their hybrids are, wait, Diesel…

    Even Ford is lining up to make a Diesel hybrid.

  • avatar

    TaxedAndConfused, well said!!

    And when the Det3 realize that ALL vehicles do NOT NEED engines larger than 3 liters and 300 hp, the US consumer might have a chance!

    Why waste TIME and MONEY “inventing”/developing unique engines for the US market? Why not finish the “clean up” of some of their best “cleaner” world market engines?

    Of course IF there is a gasoline ICE technology breakthrough … please go for it … but the same is true for diesel.

  • avatar

    Why waste TIME and MONEY “inventing”/developing unique engines for the US market? Why not finish the “clean up” of some of their best “cleaner” world market engines?

    As I have noted above, the waste of time and money comes from building products that nobody wants. You don’t see many diesels because the automakers would lose money hand-over-fist if they tried to force Americans to buy them.

    Again, there is no conspiracy. The fact that even the companies that build diesels can’t sell many copies of them in the US tells you that it’s a technology that Americans have generally rejected, at least in standard passenger cars. It’s largely viewed as a commercial application, not a consumer one.

    If Americans were taxed in such a way that gas was $1-2 per gallon higher than diesel, as is often the case is much of Western Europe, then it might be a different story. Europeans have taken to diesel largely because the much lower taxes on the fuel encourage them to choose it. It’s a financial choice, not a technological one.

    Toyota allegedly spent about $1 billion developing the first Prius, an amount that is typical for a new model launch. Obviously, it has proven to be money well spent, as sales are good and the brand building benefits are even better.

    It is not surprising to see Ford developing a diesel hybrid, as it has large European operations. But again, the technology isn’t the issue. The real issue is: Is there a market in the US large enough to be meaningful. The answer to that is clearly, “no.”

  • avatar

    Pch101, ‘The real issue is: Is there a market in the US large enough to be meaningful. The answer to that is clearly, “no.” ‘

    So, you are saying you would object to my importing an EU diesel, is that correct?

  • avatar

    So, you are saying you would object to my importing an EU diesel, is that correct?

    Please, drop this line of argument. It’s not a realistic proposal — the only person suggesting this is you. That’s about as realistic as would basing your personal financial planning on winning the lottery.

    And again, even if you could import them, there is no reason to do so if they are going to go unsold. It would a bad idea to bring over a bunch of cars just to lose money on them.

    The US market is the world’s largest auto market, and the major automakers go out of their way to target American tastes. If Americans wanted horse-drawn carriages, you can bet that you’d find them at your local Honda and Toyota dealer.

    So if we liked the taste of diesel, we’d already have plenty of them to choose from, and our parking lots would be full of them. We just don’t want them, that’s all, and there’s no point in carrying fifty models of car that nobody is going to buy.

    Above, I provided food for thought about the business climate in which the automakers have to operate. I realize that these facts are inconvenient, but these are ultimately going to determine whether or not your dream technology is going to gain a greater foothold in the US market.

    Until someone figures out how to turn a puddle into an ocean, your diesel goals will not be fulfilled, full stop. The reason that the automakers of the world are not planning on a radical shift in US consumer behavior is because they have performed a more complex version of the exercise that I have conducted above, and see the same hurdles that I do.

  • avatar

    Thanks Pch. That is all I wanted to know.

  • avatar

    Interesting article but sadly its apples to oranges. Take any gas to diesel platform you like and use like engine output comparisons and the diesel will always come out on top. Hybrids are expensive trendy products in the gasoline arena and although intial sales figures on them are high most people get tired of how underpowered they are after about 18 months or less. The high output hybrids are only marginally better than their all gas counterparts. The 2006 E-Class diesel get EPA 27/37 and is faster than the same gasline version. Not only that but diesel last longer than gasoline only versions and dont require as much maintenance (no spark plugs or wires etc, etc). Resale is another area where diesel cars out shine hybrid and all gasoline vehicles. This diesel bashing is pathethic and someone should remind the author thats its 2007 not the 80’s.

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    TaxedAndConfused and drkphoenix, good points.

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    Diesel is only a modest improvement, not radical enough.

    The ultimate solution is a gas hybrid with plug-in option for the batteries. You can get 100 MPG that way, even with a modest battery. The little fuel you still need can be biofuel. That way no more petroleum is needed, neither gasoline nor diesel. That would be nice…

  • avatar

    EJ you bring up another good point. Diesel engines can run on just about anything that burns at high compression. Any oil will basically work. There is a small following of people converting their cars to “grease cars” and albeit it’s small, the fuel is literally free. The kit is about 1000, and as with everything, it’s experimental now. And biodiesel is also made at home by many people and every you can buy B100 at pumps in some states. Diesel cars don’t want to overtake the market, but it will build momentum when more choices are available. Personally I don’t care how many hybrids are out there, i’m waiting for my diesel and sure people will not budge from their stance, but hell, both sides (diesel and hybrid) are both niche markets, so to each his own.

  • avatar

    It seems reasonable that in the future, efficient use of EVERY form of energy source will be required to maintain any where near our current “comfort level”. That said let the ingenuity and creativity begin …

    EJ and Kudo you both seem to like hybrids and that’s great. Are you aware that there are indications that PSA/Citroen/Peugeot will have 70 mpg(US) combined city/highway diesel hybrid, plug-in capable, BEFORE 2009. Oh, I forgot to mention it is electric drive (no drive train) and can operate in the EV mode for, if I remember correctly, about 20 miles.

    I happen to like a 4/5 door, 5 passenger (plus reasonable cargo) straight diesel for the moment … I only need 0-60 in 12 seconds so a relatively small (under 2 liter) TD common rail injection would probably do the job very adequately. One of the reasons I like diesel there is the opportunity to break almost completely from the petroleum industry using bio diesel.

    If spark ignition (or any other) technology can break 2,200 Btu/mile (about 660 watts/mile) with a 600 (maybe 500?) mile range … I’ll take a look provided it is affordable (including fuel costs)!

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    One of the reasons I like diesel there is the opportunity to break almost completely from the petroleum industry using bio diesel.

    That is yet another common mythology among diesel proponents. Even with an aggressive biodiesel production program, petroleum usage in the US would remain virtually unchanged as a result.

    A few statistics from the article link below:

    -US sales of diesel fuel for highway uses (as of 2000) — 33.13 billion gallons/yr

    -Amount of biodiesel that could be produced from US waste oil (assuming 50% net effective recycling rate): 170 million gallons/yr

    -Amount of biodiesel that could be produced from the entire quantity of US surplus vegetable oil: 130 million gallons/yr

    These results are not that impressive. You end up with 300 million gallons of fuel, which is equal to 0.9% of the amount of regular diesel used by on-road vehicles.

    If you take it a step further, and create an even more aggressive scenario which calls for diverting every acre of spare crop land to soybean production which is itself diverted 100% to biodiesel production, then you end up with only an additional 300 million gallons.

    Now keep in mind that under the scenario above, gasoline consumption has not been reduced at all. It also doesn’t account for all of the diesel used in other capacities, such as agriculture. On the whole, even using extremely optimistic assumptions, the effect of biodiesel production on total consumption would be virtually zero.

    And if JD Power is correct in its prediction that annual light-vehicle diesel sales increase from 3% to 7.5% market share, then these percentages will go down further still, because diesel demand will have increased accordingly.

    The level of petroleum consumption in the US is simply too great for biofuels to make much of a difference. There isn’t enough vegetable oil to put a dent in our current consumption. You could accomplish a lot more just by telecommuting one day per week.

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    Ok, Pch … you have made your point … you don’t like diesel. Even IF I can’t get bio diesel I will still be using 50% less petroleum than ANY of the current Detroit3 offerings.

    Can you name one (1) Det3 2007 offering that EPA rates above 30 mpg combined average?
    Please tell us what you can find.

  • avatar

    Ok, Pch … you have made your point … you don’t like diesel.

    That isn’t my point at all. I’m relatively agnostic on the diesel/gas dichotomy.

    Both gasoline and diesel have their advantages and disadvantages. We are, unfortunately, dependent upon both, and will need them both for the foreseeable future.

    What I am doing here is getting beyond the hype. Diesel is not a clean fuel, the fuel economy differential is not 50% as compared to gasoline (20-30% is more accurate when you match things apples to apples), and biofuels are not going reduce oil consumption by any worthwhile amount.

    You are free to like what you want, but don’t take it too far by misrepresenting the facts related to the product. I am not against biofuels, but if anyone believes that biofuels are going to reduce our oil consumption by any appreciable amount, then they are just kidding themselves.

    If you really care about consumption-related issues, the most substantive way to reduce your consumption is to reduce your driving.

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    PCH101… you say supply does not influence demand but demand influences supply. That is your rationale for concluding why diesel passenger cars do not sell well in the US. That is not true for the macro economics of the auto industry. People follow fads when it comes to buying cars. GM set out on a advertising campaign in the 90’s to sell more SUVs. They wanted to make more profit (can’t blame them) and SUVs have a higher profit margin. They said they are safer so every soccer mom went out and bought one. They are only safer because everyone else is driving big SUVs. The EV1 GM was forced to make because of California (CARB) died. Not because the market wasn’t there. Because it interfered with there campaign for SUVs. If you remember the advertising for the 1st Hummer. Did anyone remember the EV1 ads? No? Of course not. They didn’t have much. CARB eventually sold out to Hydrogen proponents and they dropped the ZEV mandate and GM snatched back the EV1 from all the buyer’s hands.

    PCH, you sound like the GM rep “there just wasn’t any demand for them”. BS!! I spent months trying to find a used diesel jetta (95 – 00). Everywhere I looked they had sold quickly. So the sellers raised prices (standard economics) way higher than book value.

    Bottom line is that the suppliers will manipulate demand as much as possible. JD Power and any other industry expert simply try their best to predict the demand for certain vehicles. Most base their predictions on current trends.

    I agree Hybrids are the future but also know that you can make a diesel hybrid just as easy as a gas hybrid. Then you will see some real nice fuel economy.

    Europe never had petroleum subsidies like we have so their gas prices shot through the roof. If average gas prices were over $4.00 per gallon for the last few years and hybrids were not available then the US would be producing almost 50% diesel cars too.

    Just like OPEC influences demand by lowering the price of crude after an oil shock (1970s). It keeps us fat americans happy and not thinking about better alternatives.

    Demand for hybrids and diesels will rise as gas prices do.

    I own my 1999 TDi Jetta and love it. I always get smiles from people who realize it gets 50 mpg. Prius owners have been getting average 55 mpg (less than the EPA original estimates and have been revised). And my Jetta can whip it on the line. Add biodiesel and I am cleaner than most cars except for NOx. I will deal with that next with an Absorber (Cerium-Oxide catalyst).

    Diesel fuel simply has a bad name in the US. Dirty, slow, noisy. My TDi is none of those things. VW was doing good selling them when suddenly an emission restriction was passed that targeted diesels. So Benz and VW couldn’t sell any during 2007. Now we have to wait for a redesign. But now Honda is in the game too. So look for plug-in diesel hybrids soon. 80-100 mpg using the latest technology. Slap in some biodiesel and be fairly clean and good to go.

  • avatar

    ‘No Escape From Diesel Exhaust’
    “Pollution levels measured inside cars, buses, and trains during
    commutes are many times greater than levels in the outdoor air
    at that same time. In some cases, the ultrafine particle levels are comparable to driving with a smoker.”

  • avatar

    The Prius C is a suprememly fuel efficient vehicle, getting 52MPG average US gallons in the real world ( and more if you try. I don’t think VW can compete with Toyota’s Pri. The Prius C is only $18K for the base model and $20K for a level 2 or 3 Prius C.

    Cheaper than a TDI hybrid and as good of MPG without the complex emissions controls for diesels.

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