By on November 29, 2013

particulate-filter-large

TUV Nord, a safety testing and certification agency, has issued a report commissioned by an environmental group that says that modern engines that use gasoline direct injection (GDI) of fuel emit more small particles in their exhausts than modern diesel engines. Particulates raise concerns over possibly causing cancer. GDI has proliferated as a means of increasing power, improving fuel efficiency and lowering CO2 emmissions but TUV Nord says that GDI engines put out 1,000 times more harmful particles than traditional gasoline engines and 10 times more than the latest diesels. The study is based on a sample size of three cars, a Ford Focus with a 1 liter EcoBoost engine, a Renault Megane with a 1.2 liter Energy TCe, and a Hyundai i40 with a 1.6 liter GDI engine.

“The cost of a filter to eliminate particle emissions from GDI cars is low (around EUR50 [~$68 US]), with no loss in fuel efficiency and a big societal benefit. Despite this, carmakers are delaying fitting filters on GDI cars,”  the Transport & Environment advocacy group based in Brussels said in a summary of the report.

Greg Archer, clean vehicles manager at Transport & Environment, said, “Cars are the largest source of air pollution in Europe’s cities and 90% of European citizens are already exposed to harmful levels of particle pollution. Carmakers’ reluctance to install cheap particle filters on GDI engines means that society as a whole has to pay the cost through more ill health.”

EU laws currently require particulate filters to be fitted to all new diesel cars but there is no requirement for gasoline powered cars. All of the cars tested by TUV Nord showed particulate emissions from GDI engines exceeding the 2017 European emissions limits, Euro 6. Fitting particulate filters reduced the number of particles in the exhaust by a factor of ~2,000, with results similar to those found in unpolluted air.

“More fuel-efficient, lower CO2 GDI engines would be a great innovation if they did not emit harmful particles. These particles can be eliminated for the price of a hands free kit. It’s time for carmakers to act responsibly and make petrol cars less polluting overall,” Archer said.

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40 Comments on “TUV Nord Testing Firm: Direct Injected Gasoline Engines Emit More Particulates Than Diesels...”


  • avatar

    Particulates don’t only cause cancer and exacerbate breathing problems, but also can help bring on heart attacks/cardiovascular events.

  • avatar
    Ishwa

    Particulates, especially small ones such as PM2.5 that ~2.5 micrometers in size, get deep into the little air sacks (avioli) of the lungs and tend to stay there. Polycyclic Aromatic Hydrocarbons (PAH) can stick onto the outside of such particulates, and are highly carcinogenic. (The smell of fresh asphalt coating or a smoky fire is due to PAHs).

    So, if you got a GDI engine (PERHAPS generating particulates galore) AND that is in a poor state from abuse (perhaps burning oil) then I bet you have a recipe for tons of particulates just coated in all different kinds of cancer-inducing polycyclic aromatic hydrocarbons.

  • avatar
    NOPR

    There will be particulate number regulations at Euro6c (2017), but they are loose enough that most automakers can (and will) meet them without the filter through engine measures. I don’t think it’s right to blame OEM’s for not putting them on voluntarily if they don’t need them to meet regulations, and he’s greatly over exaggerating how easy it is to just toss one on there. Why voluntarily add an unknown technology that most customers won’t even notice and could fail triggering expensive repairs or even recalls? The right way to implement this is by lower PN limits gradually and reasonably such that it’s required and can be robustly implemented, and I’m sure this will happen eventually.

  • avatar
    Good ole dayz

    From what I’ve heard about DPF on post-2007 diesel vehicles, they’re very problem prone in day to day operation.

    Not to mention that many (if not most) shorten engine life by injecting fuel into the exhaust valve during the exhaust stroke, some of which fuel ends up in the oil, diluting it and so causing premature wear.

    $68 dollars and nirvana thereafter is just an environmental zealot version of “if you like your health care plan you can keep it.”

    • 0 avatar
      alwayssmilin

      Good Ole Dayz In the 70s it was all about doing away with lead gasoline,Then the indian crying not to throw trash on the roads,then the superfund cleanups of lakes,ponds,rivers,etc. And all of it was complied with!! None of that stuff goes on today!! Then it was the next ice age!! Somewhere in the 80s it became global warming. They the global jihadis said in 1985 that by 2000 parts of the northeast would be underwater,Famines in America.They painted apocalypse!! That liar ERLICH was everywhere sounding the chicken little alarm. Point being nothing ever pleases the global zealots!! The EPA is a communist org!! They may have started out with good intentions but now their anti human nazis!! Today they want to regulate cow flatulance,Dust on farms,and they closed off the water supply to the San Jaquin valley in california for a 2 inch fish!! I dont buy any of this crap!! Your exactly right its the if you like your healthcare plan!! Good post!!

      • 0 avatar
        Good ole dayz

        alwayssmilin,

        There’s a joke about environmentalists being watermelons: green on the outside, red on the inside. Peddling imposed collectivism via economic / class misrepresentations went out due to the “un-spinnable” collapse of the Soviet sphere economies.

        So environmentalism became the new pathway, complete with faux crisis (as you mentioned, global new ice ages followed by global warming followed by …). Hence today we have “climate change” and “Agenda 21″ and “sustainability” as ruses for imposing collectivization and centralized planning.

        Yes, there are legitimate elements to environmentalism, but the movement has been distorted and hijacked, many current folks that promote it, while well-meaning, being the descendants of the “useful idiots” mocked (but used by) Lenin et als.

        • 0 avatar
          28-Cars-Later

          This post is essentially correct.

          Regarding watermelons, Lord Monckton may have coined the phrase, or perhaps merely repeated it:

          Lord Monckton: It’s not about the environment at all anymore. The environmentalists are merely watermelons: green on the outside, red on the inside, or I call them the traffic light tendency: Greens too yellow [afraid] to admit they are really red.

          http://www.tfp.org/tfp-home/fighting-for-our-culture/interview-with-lord-monckton-at-the-rio20-conference.html

        • 0 avatar
          golden2husky

          While the road taken created a lot of early issues, the undeniable fact is that the push for emission controls was 100% directly responsible for the cleaning up of exhaust and the subsequent improvement of air quality. Zero of this would have happened if left to “the market”. American business would have never stepped up unless they were forced to, and they fought tooth and nail at every step. Go spend a day in a marina and smell what unregulated (emission wise) industry stinks like. That was America’s roadways in 1970. A good regulatory system is not supposed to stay static; changes should be made based on new information as it becomes known, with a reasonable compliance time table. A lot of people think that “environmentalists” are in it for the money. Really. A guy like Fred Krupp from EDF could make light years more money working as a shill for ExxonMobil than he does working for a nonprofit environmental advocacy outfit.

          • 0 avatar
            alwayssmilin

            GOLDEN2HUSKY If you read more closely you would see that neither me or the other posts are claiming that it was a bad thing to make certain changes. I am glad we got away from lead gasoline,and cleaned up the waterways and dont litter like we did. There was no need for congress or the president to make a beaurocracy with unlimited power EPA !! States should have more control than feds!! Either way congress should write bills and pass them the constitutional way. Not make the EPA and give them all the power . But like I stated we live in a much cleaner world and yet the greenies or reddies!! Never stop chipping away!! Wanting to push a lying agenda AKA GLOBAL WARMING!! is wrong and them telling farms what fertilizers they can use,how much food they can grow,and on and on!! If you cant see the corruption and eroding of rights then I feel sorry for you. Pointing to a few well meaning descent people does’nt make the EPA a good thing!!

  • avatar
    jpolicke

    $68 for a particulate filter? One of three things is occurring here:

    Filters for gas engines are significantly cheaper than for diesels;

    VW grossly overcharges for replacement TDI filters (quoted price $6000);

    The TUV hasn’t got a clue as to what these filters actually cost.

    • 0 avatar
      Brian P

      VW DPF filter is nowhere near $6000. If you were quoted that, find a different dealer or an independent mechanic. But the oost to replace the part in the aftermarket is not even remotely related to what the part actually cost to make. (For one thing, on that car, you have to remove the right drive shaft to get enough clearance to remove and install the DPF. They don’t have to do that on the assembly line …)

      VW’s cost as an OEM is nowhere near what a retail aftermarket customer pays. It’s quite possible that the actual manufacturing cost of the part, not including any of the extraneous markups and distribution chains, is below $100 per unit. I suspect that TuV’s $68 doesn’t include ANY engineering, development, or maintenance costs – and that’s not really fair, either. The truth is somewhere between the two extremes.

      • 0 avatar
        jpolicke

        The dealer was charging VW that much for a warranty repair; this implies to me that they expected to receive it and that therefore, VW considers that amount to be appropriate. The disassembly may add a couple hours labor time but even if you remove all the labor cost you still don’t get down to a component price anywhere near TUV’s fantasy numbers. And this unit is not available on the aftermarket – if I had gone to an independent mechanic (because I prefer to pay for a warrantied repair?) he would likely have obtained it from the same VW dealer’s parts counter.

        Aftermarket generic catalytic converters have finally made it near the $68 price point; I find it hard to believe that particulate filters – a much newer and more complex technology – is going to be anywhere near that inexpensive for a long time.

  • avatar
    MrGreenMan

    At some point the combined insanities of bureaucratic approximation to paying the cost of maintaining road infrastructure – whether it’s CAFE or it’s a displacement tax and differential fuel taxes to maintain some “expert’s” idea of what a good price ratio is – will come crashing down.

    Hopefully it’s sooner rather than later, but having dedicated funding for road infrastructure (i.e., not a general fund; I know I dream of Jeffersonian-era dedicated taxes, but some states still work like that) and then having something on the consumer side that translates more directly to how much you use and damage said infrastructure would mean avoiding automotive perversions that hit a number but really don’t do anything to increase either longevity, joie de vivre, or even fuel economy.

    And, by perversions, I mean things like EcoBoost — powering a 2014 Ford Fusion with a 1.6L or 2.0L turbo-charged engine to motivate something with a higher curb weight than a mid-2000s Ford Five Hundred, panned by Big Al for being underpowered with a 200-ish HP/200-ish torque NA V6, getting similar fuel economy, and, at least in my random sampling in both from-stop and rolling two-lane blacktop, the Five Hundred can out accelerate the new Fusions, even when the new Fusion driver is really trying to pretend it’s an Aston Martin. I don’t care if it’s a Kia Optima “GDI” or a Buick Regal GS – these turbo fours are less enjoyable, not better at fuel economy because nobody can drive with the glass foot required to pretend they’re a regular I4, and slower than a wheezy, NA V6 of yore.

  • avatar
    ash78

    It’s sad and entertaining to see the regulatory bodies on either side of the Atlantic wrestle with many of the same issues, but with different approaches. First, Europe cares about CO2 only (grams per distance), but diesel fuel is subsidized and this puts more diesels on the road. Meanwhile, said diesels are mostly unavailable in the US because the EPA has particulate standards that can’t be met without complex filters or urea that have to be developed for our market (and then were initially unable to be sold in several large states). Then more GDI engines become available in Europe and diesel subsidies start to disappear, leading to more gassers. But manufacturers are finally offering good diesels in the US, which are too late and often equalled (on paper) by these new GDI gassers. Meanwhile, the EPA is changing its system to the new footprint-based mpg standard for CAFE and Europe is now suddenly focused on particulates, which were truly an issue all along (especially for diesels) but are only now really brought to the forefront because the GDI engines are even worse than the clean diesels.

    It makes my head hurt. One thing that nobody can refute in any way, however (unlike, say, AGW climate change) is that a lot of combustion-derived particulate matter is carcinogenic and causes all kinds of health problems. I think the European bodies are finally under pressure that their idealistic, global focus on reducing CO2 has contributed to ignoring the local pollution issues that are killing people every day, right now, right here.

  • avatar
    AMC_CJ

    What a crock full of shit.

    The filters on diesels engines are becoming hugely problematic and are becoming a large costs of repairs/resources for trucking fleets. YOU DON’T WANT THIS SHIT ON YOUR CAR!!! Trust me.

    Even the article, the firm itself said “it could possibly cause cancer”. Well yeah, and drinking 100gallons of water in hour might possibly kill you too. What’s the point here? Scientist have to put food on the table. So hey, here is something we think might be a problem, but oh, luckily for you, we know the solution too.

    But for god’s sakes people, pull your head out of your asses. These things add costs, weight, inefficiency, and expenses to every vehicle. Enough is enough.

    • 0 avatar
      Wheatridger

      Those filters, and all the other bothersome emissions controls you probably despise, are what protect us from the hellish environmental conditions of China. In one industrial city there, particulate pollution was 100x the average for Manhattan!

      I like my cool
      cars, but I also have to breathe, ya’ know?

      • 0 avatar
        28-Cars-Later

        The pollution in China would have happened in the US if large industry wasn’t artificially exported out starting the in 1970s. How many diesel engines equal one coal fired power plant? I would guess a ratio of thousands to one. Basic emissions controls aren’t necessarily a bad thing but like anything taken to an extreme it creates economic and unnecessary technical problems. Pollution will continue to get worse as a whole until civilization moves out of the Oil Age, lifestyles of existing populations are reduced, or populations themselves are reduced.

      • 0 avatar
        AMC_CJ

        No not really. Car emissions are at a good point. They barely spew out anything. This is taking things to the extreme for no real benefit. A point of complete and utter diminishing returns.

        There always has to be a new threat, a new crisis, or these people go out of business. Well, they just found it. Particles, they’re going to kill you, you know, but hey, these people got the answer already. What a useful bunch of people, better keep them around.

        I’m just trying to preach reason here, based off real world accounts of being a professional who works on this stuff everyday. So you know what, if you want to be saddled down with expensive repairs, cars that can’t go anywhere because of restricted filters; the stuff I see on a weekly basis, just go ahead. I’ll be driving my completely desmogged 78′ Chevy by you while your car flashes a “exceeds soot level” message at you. AAA might tow it away for you, but whose going to pay that $1000 bill to remove the filter, have it cleaned out, and re-installed? All for something that is just so unnecessary in the first place.

        • 0 avatar
          golden2husky

          For the traditional emissions (NOx, CO, HC) you are probably correct. At a given point, the numbers have to be considered good enough, and perhaps a much better benefit would be making sure the hardware used works for the typical life of the car rather than go for that small remainder. Over the life of the car the benefit would likely be far better that way, and less costly as well.

          Regarding diesel exhaust, the problems caused by particulate cleanup depend pretty heavily on use of the vehicle. I have a friend with a diesel Chevy HD 2500 pickup and in 50K of use, has had zero problems with the filter/burnoff system. The tailpipe of his truck is amazingly free of black crap. Not so his co-worker’s pickup which is the same model. He has had several dealer visits with his truck over filter issues. Difference? My friend tows with his truck and it gets a heavy load and a good workout on occasion. His friend commutes short distances with his and it rarely sees any work. Either way, the system as it stands needs work because it can’t cope with likely use patterns.

  • avatar
    FractureCritical

    If a particulate filter on a gas motor only costs $68, how come the one on my old 2010 Jetta TDI was $2200?

  • avatar
    Wheatridger

    Now you tell me about this! I just spent $100 to investigate a sooting problem with my GTI. It’s a superlative car in great condition, but just 20 miles after a car wash, I can write my name on the tailgate. Tiny black particles proliferate there. They wash off easily with water, which told me they weren’t regular road dirt. Why did my 2.0T seem sootier than my old ’02 TDI? And why didn’t my Tiguan, with the same engine, show nearly as much soot?

    So I took the GTI to one of the top-shelf Euro performance shops in Denver. Their verdict: “nothing’s wrong, but it drives like it has a chip tune.” I feel better now, knowing that the soot is not a bug, but a feature. But I would have never asked for it– the car is stupid fast, sp powerful that I never feel like I can drive it hard. And I get no satisfaction from soot emissions, unlike the poorly toilet trained jerks who “blow coal” out of steamboat stacks in their diesel pickups, like frightened squid squirting ink.

    My remaining questions is, GDI engines have been around for seven years or so. Why am I just learning about this issue now?

    • 0 avatar
      bball40dtw

      I dunno why you are just learning about it now. The VW forums have plenty of complaints about carbon build up and soot. What year is your GTI?

      The FSI engined GLI I had produced more soot than the later TSI engined GTI I owned.

      • 0 avatar
        Wheatridger

        It’s an ’09, the last of the Mk Vs, with the TSI engine. Apparently the same engine as the ’13 Tig, though it might be programmed differently.

        The sooty talk I’ve read on VW forums always discusses carbon buildup on the intake valves, not carbon blowing out the rear.

        • 0 avatar
          bball40dtw

          Yeah, the carbon blowing out the rear isn’t as common. I had an end of the run 09 MKV GTI as well. From all I’ve heard, its just a normal thing. You car is blowing out the carbon instead of sticking it all to the intake I guess. As long as its not throwing a CEL, you are probably fine.

          I have a MKT with teh 3.5TT now. Even that engine gives me carbon deposits on the tailpipes that I clean twice a year.

          Another eason why the GTI may be spitting out soot and not the Tiguan is that the GTI is programmed to run pretty rich. Even though its the same engine, it feels so much different in the GTI.

          • 0 avatar
            Wheatridger

            It’s still a powerful engine in the Tiguan. But it uses so much more gas, I’d imagine it was the richer-running engine.

          • 0 avatar
            bball40dtw

            I like the 2.0T. Its excellent paired with the DSG transmission in pretty much all applications. I miss the transmission more than the engine now. The Ford/GM designed 6-speed just seems lazy in comparison.

    • 0 avatar
      JimC2

      “…unlike the poorly toilet trained jerks who “blow coal” out of steamboat stacks in their diesel pickups, like frightened squid squirting ink.”

      I’m stealing this!

      In return, I offer you my own original prose regarding these kinds of motorists, “Inbreeding is a cruel thing to do to a child. So please, step away from your cousin!” (Just the first part, by itself, works almost as well.)

  • avatar
    PrincipalDan

    Well Boys and Girls, go buy your 3.6 DI GM V6 now while you can still get the less complicated model.

  • avatar
    28-Cars-Later

    The fact the enviro-thugs and emissions fascists missed this is enough for me to suggest they are incompetent and should be ignored in the future.

  • avatar
    Charliej

    My question is why is a gas direct injection engine putting out more particulates than a port injected engine? They are both burning the same fuel in the same air. Why would one put out more particulates than the other? If I remember my college chemistry, they should both burn the same. It would seem to me that the only thing that could make higher particulate emmissins would be an overly rich. mixture. If I am mistaken, could someone please enlighten me?

    • 0 avatar
      JimC2

      It’s not quite as simple as fuel:air mixture being right or wrong. Fuel atomization, mixture distribution, and a few other phenomena going on inside the engine produce incomplete combustion.

    • 0 avatar
      Lou_BC

      @Charliej – I am surmising that DI engines provide fuel later in the combustion cycle at a point where cylinder temperatures and pressures are much higher. A DI gasser starts to behave more like a diesel. That must create more “fine” particulate.
      We are talking about objects microns in size. Those small particles can penetrate more deeply into tissue. Once they enter a cell, they can cause mutations in DNA. If you happen to be a person with the genetic predisposition to cancer, that fine particulate becomes the “on” switch of a process no one wants to get.

      • 0 avatar
        Big Al from Oz

        @Lou_BC
        Direct Injection allows the fuel injected near TDC.

        Because of this situation the ignition can be retarded much closer to TDC. This allows for less pre-ignition and increased compression (more power) with use of less fuel.

        In an ‘old’ carby induction system the actual ignition and combustion process was much more advanced allowing for the combustion process to be hotter and more complete.

        So with the cooler combustion process of a DI you achieve less NOx, less CO2 through less fuel, but more particulates that can’t be ‘burnt’ off through a cooler combustion.

        Also, I would like to see the difference in these figures between a variable twin cam and a fixed single cam engine.

      • 0 avatar
        Big Al from Oz

        @Lou_BC
        I got diesel and gasoline ass-up concerning DI (common rail).

        DI can increase NOx and it is supposed to reduce particulates.

        THE INCREASE NOx Paragraph,
        However, due to higher cylinder heat and pressure, NOx and particulate matter emissions from direct injection gasoline vehicles can increase, the latter by about 6% (Gable, 2008). Under low power demand conditions the gasoline engine is running in lean burn mode, where the fuel to air ratio is not ideal for use of the standard three way catalytic converter to remove NOx from the exhaust gases. Lowering NOx emissions from direct injection gasoline engines requires different types of catalytic converters.

        http://climatetechwiki.org/technology/ice_improvements

  • avatar
    Charliej

    Lou, there is no combustion cycle until the fuel is injected. I did not specialize in combustion studies when I was in college, but I did major in chemical engineering. That was a long time ago, but gasoline has less carbon atoms in it than diesel fuel has. Carbon is what makes up the bulk of particulate matter in diesel exhaust. I would like someone who is more up to date on this than me to explain how fewer carbon atoms equal more particulate emissions.

    • 0 avatar
      Lou_BC

      @Charliej – sorry, traditional engines had an intake stroke followed by a compression stroke then combustion. They could not traditionally run higher compression due to pre-ignition. I should of worded my comment differently but higher combustion temperatures IIRC are responsible for more NOx emissions. Not all of the fine particulate needs to be carbon based. Sulphur oxides like nitrogen oxides can also be a source of fine particulate.
      I’m not a chemical engineer but I do have to deal with the carcinogenic effects of substances in our environment.

      This report is only based on 3 engines. More research needs to be done.

  • avatar
    Charliej

    Do Gas direct injection engines control combustion temperature with exhaust recirculation like port injected engines? As far as I know, the combustion temperatures are no higher in a GDI engine than in a port injected engine. GDI engines generally have a higher compression ratio than port injected engines. This allows cramming in more fuel and air per stroke, but would not necessarily result in higher combustion temperature.

  • avatar
    shaker

    But think about the similarity between diesels and GDI engines: The fuel is injected into highly compressed, hot air just before ignition; with the port injected engine fuel is essentially “mixed” with cool, low pressure air on the intake stroke.
    These differences are likely enough to cause aggregation of some compounds into non-flammable (or poorly burned) particulates.

    Disturbing that this was never revealed.


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