By on October 12, 2010


There’s no replacement for displacement? Sure, as long as you own an oil well. If you want to save gas, there are three ways to do it:

  1. Make the car as light as can  be (you can’t fool Newton.)
  2. Use the smallest amount of displacement you get get away with, and make it up with direct injection, a turbocharger, and computer smarts.
  3. Combine 1 with 2.

And what’s the easiest way to reduce displacement? Lose cylinders. That way, you also lose a lot of internal friction. If “Laufkultur” is part of your vocabulary, don’t read further, you’ll get sick. If you want to sick it to Big Oil, by all means, read on.

Automobilwoche [sub] writes that 3-cylinder engines  are pretty much common, for instance at Volkswagen, in the Suzuki Alto und Splash, in the Opel Agila and the Nissan Pixo, just to name a few (in Europe.) Now, hats off to the next engineering feat: Two cylinders.

Fiat’s new 500 is going back to the future. The 1950 vintage original had two pots that turned half a liter of „displacement“ into 18 horses. The new engine has nothing in common, except for the two cylinders. The 875cc (that’s 53.39ci)  MultiAir engine dispenses with a camshaft and has totally independent and variable valve control.

“That alone stands for 10 percent more power, 15 percent more torque and 10 percent better mileage,” says Thomas Kern of Fiat Frankfurt. The enginelet makes 85 horses out of its 875cc and brings the Fiat 500 to a top speed of 173 km/h (107 mph), while using only 4.1 liter / 100 km (57 mpg, non-EPA), while producing only 95 g of CO2 per km.

At VW, they are working on a two cylinder diesel that should bring even better mileage than the benchmark 100km (235 mpg – yes, you read that right, non EPA though.) The L1, a new generation of Piech’s 1 Liter Auto, is propelled by a two cylinder diesel with 0.8 liters displacement. In regular mode, it delivers 27 horses. Push the „Sport“ button, and power will jump to exhilarating 39 horses.

Sick already? We warned you.

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64 Comments on “Want To Save Gas? Get Rid Of Cylinders...”


  • avatar
    ajla

    If you want to save gas, there are three ways to do it…
     
    What about gearing?

    • 0 avatar
      G.D.

      Exactly.  Or this one:
      Slow down.
      Air resistance is not your friend.
      How about this from the files of the foolhardy: near 300hp in a Camry?
      More than one (or 3) way(s) to skin a cat.

    • 0 avatar
      nonce

      Beating the EPA estimates isn’t that hard, but you can’t do it at 80mph.
      I got over EPA mileage, with two kids in the back seat and a trunk full of camping equipment while running the AC. You just need to care a little bit.

  • avatar
    Paul Niedermeyer

    The Laufkultur will be mitigated to a substantial extent with balance shaft(s).
    The Fiat engine is pretty remarkable, having read several articles on it. The future is at hand.

    • 0 avatar
      Acubra

      Definitely not the future that I want. Another step towards disposable, throw-away-garbage-once-past-warranty contraption that no-one really wants but is made believe that they do or plainly forced into via all sorts of taxation on mobility.
      Ni thanks, I’d rather stick with my boxer-6 or a Vee-8, thank you very much. I’ll let others drive “cars” that sound like a farting rabbit and are worth as much.

  • avatar
    SVX pearlie

    For a city car, sure. Not sure I’d want a 2-banger for highway travel…

  • avatar
    krhodes1

    Most excellent! I like small cars with small engines that FEEL fast, even if they are not actually fast. Actually fast cars usually feel rather slow, and that gets you in trouble with the Highway Revenue agents. I find it hilarious that the average American seems to think they NEED 300hp, when the fastest speed limit in the country is 85mph, a speed comfortably within the grasp of my 70hp 1296cc Olde Englishe Crocke. A modern 1L triple will do that all day every day.

    • 0 avatar
      MikeAR

      Actually, we need 400+ hp here. You can never have enough horses after all. You must not know much about this country.

    • 0 avatar
      FleetofWheel

      Dangerously slow merging acceleration, shaking, noise and vibration are anything but ‘comfortable’.
       
      300 horse power is a good round number for any mid size car. This allows dignified and satisfying motor travel.
       
      Larger sedans and sports cars should have more power of course.

    • 0 avatar
      Jacob

      It’s highly subjective, but in my opinion, a smooth 200HP engine mated to a nice responsive 6 speed automatic transmission is more than adequate to power a midsized car like Camry for normal driving. Anything more than that is just for fun or ego boost. I know this, because my Ford 500 (bigger than Accord I think) has only 200HP and I never miss additional horses.

    • 0 avatar
      Acubra

      @MikeAR – well said!
      Most of that “small is cute” trash comes from the city types who never been past the Big City limits.
      Jacob, your 200 hp feels right only because the XXX lb-ft that comes along with your 200 hp are right. And here you either have to have a reliable, inexpensive and durable displacement, or a live fast-die young turbocharged frenzy.
      I’d say, 6 pots, 3 liters and 200 hp/200 lb-ft is a good starting point of a good passenger car.

    • 0 avatar
      sportyaccordy

      Most Americans drive 4 banger Accords / Camrys… I don’t get why foreigners think we are so power hungry.

  • avatar
    M 1

    Leading with “No replacement for displacement” in an article about fuel efficiency is like beginning an article about cirrhosis with a review of the top five single-malt whiskeys. And yes, I do equate econazis designing cars with dying of liver failure: it’s wrong and hideous and god awful, and there’s a good chance it’ll keep happening anyway.

  • avatar
    Steinweg

    Despite my utter hatred and well-founded mistrust of all Chrysler products, even if rebadged for sale here as a Chrysler I would buy that MultiAir 500 . It’s just so neat.

    • 0 avatar
      Acubra

      You obviously are not familiar with unreliability record of Italian products, their proud standing only challenged by that of the British.
      Besides, your Chrysler-bashing of ALL its products only shows your total lack of knowledge and experience.

  • avatar
    jaje

    Our cars’ waistlines have grown too big b/c of the growth of our own waistlines.  Now we have single occupant 5k lb vehicles as daily drivers that get at best 20mpg real world (often much less).  IMHO, hybrids are not the answer as they add excess cost in the short and long run, more greenhouse gasses in production, and more complicated and expensive repairs.  However, adding proven technologies that cost significantly less, downsizing engines, and lightening / downsizing the size of the car we “need” / not want is just common sense.

  • avatar
    friedclams

    I have a single-cylinder motorcycle. They’ve been around for years. They work great and are very simple… I’m sure they could be refined for automotive use with all the tech goodies.

  • avatar
    alex_rashev

    Might as well get rid of ALL pistons.

    Direct-injection, single-rotor, start-stop engines will rule the gasoline compact car world, mark my words. Not least because they’ll fit just fine right under the rear seat where they belong.

  • avatar
    Zackman

    O.K. I’ll buy that. BUT: How will a car maker get away with less weight? I’ve been bringing that subject up for quite a while. How light will the feds allow one to build a car that seats four that weighs less than 3000 lbs? Would Chevy be allowed to build a next-gen, same size/weight Metro?

  • avatar
    akitadog

    If the 2-cyl is a 4-stroke engine, then what degree of crank will it have? If it’s the standard 180 degrees, then there will be two power strokes in 1 rotation, meaning a rotation with no power. The engine will slow down (ever so slightly) every other rotation.
    If it’s a 0 degree crank, then we’re talking enough vibration to rattle your fillings out. I don’t think a balance shaft will do enough to quell that racket.

    • 0 avatar
      johnny ro

      I do. My GS500F has two cylinders, I forget but think its 180 degree crank, balance shaft smooths it out mostly. If it had rubber mountsit would be smooth indeed.
      My SV650 is smooth with two in a V.

      For zero degree cranks, that would be odd. usually they fire cylinders one then the other, not both at once.  A WWII navy outboard motor was 4 cyl zero degree crank if I remember right. All 4 cylinders fired at same time. An opposed four 2 stroke.

      Try 90 degree crank. That would help with high HP, to get the power to the ground. Yamaha is doing that with its latest fast bikes. I forget the lingo they use. Irregular firing pulses give tire time to reconnect with road. It probably matters more with 16,000 rpm than with 3,500 like on a car.

    • 0 avatar
      Brian P

      In the motorcycle world, there are quite a few firing patterns (and counterbalancing approaches) for two-cylinder engines. With parallel-twins, both the 360 (or 0, depending on point of view) degree cranks and the 180 degree cranks are in use.
       
      Kawasaki parallel-twins historically have had 180 degree crankshafts. There are indeed two firings in a row followed by a full revolution without any firings. Untold thousands of Ninja 250’s, Ninja 500’s, and Ninja 650’s are all like this. A balance shaft is still needed because the engine has a strong end-to-end rocking couple. The uneven firing pattern is noticeable with the engine idling but quickly disappears at the higher revs that these engines are designed for.
       
      BMW F800’s have 360 degree crankshafts – even firing order but heavy first-order vibration if not counterbalanced. Instead of a balance shaft, they have an extra crank journal that is 180 degrees apart, which operates a counterweight using an extra connecting rod, which offsets the weight of the pistons. It is also possible to do this with a counter-rotating balance shaft, although to do it properly you need TWO counter-rotating balance shafts to avoid having a rocking couple. And, of course, historically, the original Fiat 500 two-cylinder engine had a 360 degree crankshaft and no counter-rotating balance shaft … they just had a really soft engine mount at the back, basically just a coil spring, so the engine could judder and vibrate around doing its own thing without transmitting *too* much of the noise to the chassis.
       
      Many, many motorcycle engines have 90-degree V-twins. Ducati (almost all), Honda RC51, Suzuki SV650 and SV1000 and all of their related cousins, are all like this. No balance shaft is needed for perfect primary balance. Firing pattern is slightly uneven (270-450-270-450 etc).
       
      Some other V-twins have close to a 90-degree angle, but either use a balance shaft, or have crankpins separate for each cylinder and offset by an amount related to the amount that the V-angle differs from 90 degrees.
       
      Let’s not discuss the Harley-Davidson 45-degree V-twin with neither counterbalancer nor offset crankpins …
       
      A little engine that spins fast need not be rough, if it’s properly balanced and spinning fast enough so that the space between firings is not noticeable. One of my motorcycles is a 125cc 4-stroke single. It’s smooth enough, because this engine lives above 6000 rpm, and it’s counterbalanced. Having a tiny piston and con-rod that hardly weigh anything helps, too.

  • avatar
    Facebook User

    I’d love to try a 2 cylinder.
     
    1098R comes to mind…

  • avatar
    Jerome10

    I’ve just recently had the pleasure to drive a 1.2L 3cyl gasoline VW Polo.  It was terrible.  The feel and sound are just god-awful.  Best part about it was that it had no power and not much weight on the front end, meaning I could beat the living crap outta the thing in the hills and it never had a chance to make me wet my pants in fear.
     
    No thanks.

  • avatar
    L'avventura

    Inline-2s are going to be very common especially for the developing world.
     
    Other then the 2-cylinder in the Tata and Fiat, Daihatsu has shown a turbo-charged inline-2 designed for kei-cars in Japan, and Toyota has already announced a 800cc inline-2 for emerging markets.  Most automotive makers targeting the developing world have probably already have something in the wings.
     
    Also, I’ve always thought that an inline-two would be ideal as a range-extender engine for EVs.  They are small and light-weight, furthermore they greatest undesirable reciprocating vibration comes at idle or at low-rpms for inline-2s, something that can be avoided for a generator engine that operates at a low rpm range.
     
    Another thought would be a flat-twin, something that Subaru could make for smaller cars.  Small cars now are fairly-wide and it would be a much better choice then the 1.5L flat-4s Subaru currently uses.  The cost and complexity would be more then a inline-2, but a horizontally opposed flat-twin would be much better balanced.

  • avatar
    Jerome10

    How about a good ol’ V-Twin?

  • avatar
    Autojunkie

    Nearly 60 mpg/100 hp in the Fiat 500 with a manual, or optional DCT, for around $15K??? 

    Sold!

  • avatar
    carguy

    Less cylinders doesn’t have to mean gutless propulsion for econoboxes. I’m sure that BMWs planned 3 cylinder direct injection turbo charged engines will be as much fun as their current offerings.

  • avatar
    stevelovescars

    I’ve always believed in the notion that it is much more fun to drive a slow car quickly than a fast car slowly.  I suppose I could be swayed that driving a fast car quickly is even more exhilarating, but not necessarily during my daily commute. 

    Case in point, I always got a grin revving the piss out of my 1.6 liter Miata (118 hp and about 2,200 lbs) while my Porsche 911 always felt like I was loafing even when going 90 mph.  In bikes, I started with a 650 twin (Honda Hawk GT) and eventually “worked myself up” to an 1100 cc sport bike and a BMW touring bike.  I then ended up buying a 500cc single and ended up selling the other bikes and keeping the thumper… just more fun at the speeds I could legally go on the street.  I just found myself jumping on the little bike for any ride shorter than 4 hours… which was pretty much every ride I had time to take.  That big thumper had a balance shaft that managed to keep the vibration tolerable… a car with flexible motor mounts would likely make it even less troublesome.

    So I guess I’m all for the idea of lighter cars with moderately powerful engines.   

  • avatar
    TrailerTrash

    Bertel, Mazda has promoted the philosophy of weight loss for a year now and I like this.
    And I agree that small, powerful engines should be the future.
    But what about longevity?
    It is nice to talk about MPG as the goal, but isn’t driving in the good ‘ol USA different from that of Europe.
    Not short term, but long term?
    Wouldn’t all savings be blown away in the winds of time if replacing engines every 100K is the result?
    Have materials been improved enough to withstand the test of time?
    Or are we talking the Bic Lighters of engines here?
    Use them and replace them.

    Can a 2 keep up with cross USA driving and carrying the load of a family?

    • 0 avatar
      TrailerTrash

      I guess, to answer my own question…
      There is a reason we don’t see 2 cylinder trucks, tractors or other heavy equipment.

      Power and longevity.

      MPG is just peachy, but then you need to make it through the hills…and the payments.

    • 0 avatar
      Brian P

      It’s not a matter of longevity; it’s more a matter of using components that are of a practical size. An enormous displacement engine with very few cylinders cannot spin fast and will be extremely rough-running and would need extreme countermeasures against vibration.
       
      Many, many 1 and 2 cylinder motorcycles will go well over 100,000 km without overhaul as long as they are maintained properly and not abused, and those are engines that aren’t necessarily designed for extreme longevity in many cases. Plenty of single cylinder scooters and small motorcycles in the developing world get huge mileage put on them. The number of cylinders doesn’t have much to do with longevity. How properly-designed the engine is, has a lot to do with it.

    • 0 avatar
      TrailerTrash

      It IS about longevity.
      And all these references to Bikes is silly.
      They carry nothing.
      They do nothing work wise.
      We are talking about city go-cars, and obviously not trucks.
      This small 2 cylinder engine just becomes and exercise in intellectualism.

      Keep this real.
      In my opinion mentioned above, small is cool…IF the car is small, the longevity isn’t as we now need it or the driving isn’t what we Americans have come to expect.
      I rather believe no 2 banger is going to haul your kids to and from the school dorm every semester.

      Enough…we soon will see

  • avatar
    Sinistermisterman

    Sounds like a great idea these small engines. And to all those who say that ‘merging with an engine that small is dangerous’ – that’s rubbish. You just rev the nuts of the thing. I’ve had 1.1 Ford Fiesta sh*tbox doing 70-80mph by the time I reach the bottom of the on ramp.
    On a different note, does anyone know if these engines are of an interference design? Only I’d be worried that with no camshaft if something went wrong with the cars electrics (this is a Fiat we’re talking about), then couldn’t you end up mashing your valves to bits?

  • avatar
    Uncle Mellow

    I’ve driven a VW three-cylinder.I had to check carefully what fuel to put in , because it sounded and felt like a diesel, but it actually ran on petrol.
      The main problem with the Fiat twin is that it costs more than their 4-cylinder engine.

  • avatar
    Brian P

    The article is not correct about this engine “not having a camshaft”. MultiAir still uses a camshaft – although it operates the valves through a hydraulic connection with a solenoid valve to change the way the camshaft operates said valve. Still most certainly has a camshaft, though. And the valves are still closed by good old-fashioned valve springs.
     
    As for “needing” 200 horsepower to get around … that’s absurd. The vast majority of drivers do not accelerate faster than roughly a 15-second pace from zero to 60 mph – not even when they are merging onto a motorway. The vast majority of drivers of 200-horsepower cars would crap their pants if a competent driver showed them what the car was actually capable of doing.
     
    I’ve never owned a car with more than four cylinders and never more than 120 horsepower or thereabouts, and lack of power has never been an issue. I tow a trailer weighing about 1500 lbs with a Jetta TDI, and it gets the job done. No, it’s not “fast” with the trailer in tow … but one shouldn’t be driving “fast” with a trailer in tow anyway. It’s fine.

    • 0 avatar
      JuniperBug

      Agreed!

      I was always amazed by how much faster I was in my 100 hp, stock, Jetta than all the 270 hp Camrys, et al. It’s astonishing to see the gap between what people think they need and what they actually use. Even when I drove a 10 year-old minivan with blown shocks, there were few times I could make it through a curve without being slowed down by someone in a new, fancy car in front of me.

      That Jetta was good for about 115 MPH, by the way, and would cruise at 90 for hours at a time. VW even put a second set of tire pressure values on the door jam if you were planning on driving above 100 MPH. How many people actually ever go faster than that?

      More power is nice when you can swing it, but people who say that merging is unsafe without 200 hp are deluded, and quite possibly the type who never rev an engine above 3000 RPM. I agree that most people merging onto the highway take a good 12-15 seconds to get to 60. My VW did it in about 9-10, and there was always someone in the way if I tried to wind it out.

      We’re obviously still doing very well as a society if we have the luxury of pissing away money and resources because we want to get to cruising speed a couple of seconds faster or without having to hear the engine rev. Either that or our priorities are very skewed…

  • avatar
    Mr. Gray

    As a sport compact enthusiast, the concept of lighter weight cars is an exciting prospect for me. Remember what Honda tuners proved could be done with small displacement? If these cars become commonplace, I’m excited to see what tuners can do with them.

    I believe Collin Chapman said, “add power and you go faster in the straights. Add lightness and you go faster everywhere.”

  • avatar
    CarPerson

    2.  Use the smallest amount of displacement you get get away with, and make it up with direct injection, a turbocharger, supercharger, four valves per cylinder, independently variable intake and exhaust camshaft timing, and computer smarts.
     
    There, fixed it.
     
    WAIT! Didn’t I just read one of these is sitting in a showroom at this very moment???

  • avatar
    carve

    Another great way to improve efficiency is this: Increase the engine’s power to weight ratio.  A smaller, lighter engine generating the same power can use a lighter suspension to carry it, which can use lighter wheels and tires, which combined requires less chassis strength, lightening that component, and now that the whole car is lighter, we can make due with even less power, which lightens all those elements again AS WELL AS the transmission and drive-line, and on we go.  We’re only just now beginning to see this philosophy.  The new Sonata is a great example- it’s designed from the star to NOT accommodate the size and weight of a V6, and gets great mpg for a car it’s size, despite Hyundai having a poor track record in this department.

    Powerplant power/weight ratios have improved a lot in recent years, but there are still new avenues to try. Ethanol-injected high-compression engines would be a start. Two strokes have fantastic power to weight, and now that direct injection is common, and think we could make them about as clean as a four stroke.

  • avatar
    Sugarbrie

    Unless things have changed, I never have seen too much difference in mileage between a gas 4 cylinder turbo and a 6 cylinder including the Audi/VW 1.8T and 2.0T; and Mercedes 1.8L, 2.0L and 2.3L Kompressor
     
    All the 4 cylinder models have is a lower price.  More money for gas I guess.
     
    Now non-turbo 4 cylinder do get better mileage. So the turbo boost must use more gas or something?
     

    • 0 avatar
      Zackman

      Two identical cars, one with a six, one with a four – the six works less harder to move the same mass. Old case in point: My 1990 Acclaim – 2.5L four = 28 hwy mpg. My 1994 Spirit – 3.0L six = 30 hwy mpg. Not a scientific exercise by any standard, especially in 2010, but may still be true.

    • 0 avatar
      golden2husky

      Two identical cars, one with a six, one with a four – the six works less harder to move the same mass. Old case in point: My 1990 Acclaim – 2.5L four = 28 hwy mpg. My 1994 Spirit – 3.0L six = 30 hwy mpg. Not a scientific exercise by any standard, especially in 2010, but may still be true.
       
      Your 4 cylinder Acclaim came with a 3 speed transmission with a lockup converter, IIRC.  Your 3 litre Spirit had a 4 speed overdrive transmission – the dreaded A604 Ultradrive.  That is likely the primary reason for the better mileage…

    • 0 avatar
      hans007

      i drive an audi a4 with the 2.0t.   the first model year they offered the 3.2 L v6 also .
      from what everyone has said on the reviews etc, the 2.0t and 3.2  L accelerated to 60 within .1 seconds of each other.  (some mags had the 2.0t winning since the car was lighter)
       
      And the main difference was the v6 would pull ahead over 100-110mph (it also had 45 or so more peak hp).   that said,  the i-4 isn’t even tuned to its maximum potential and a reflash would make it faster than the v6 (which you cant reflash for more performance).
       
      the v6 also cost like $3000 more  and used 3-4mpg more.

  • avatar
    Tosh

    It’s pissing into the wind to try to improve on the efficiency of the heat engine. (Look up “Thermal bottleneck”) Wake up: The future is electric motors…

  • avatar
    Nick

    Why the focus on inline-2s instead of horizontally opposed?  Or triple arranged in a ‘circle’, the way old air-cooled radials were?

  • avatar
    18726543

    One unmentioned trick that my Civic VX throws in the mix is the use of a lean-burn mode.  I realize this is only really sustainable at highway speeds and under low demand, but considering the modest gains large displacement engines reap through complex systems like cylinder cancelation during the same circumstances, air/fuel ratio modifications seems like a better plan.  IIRC, it accounts for a 25% fuel economy increase when activated sustainably in my Civic.  I know back in the day there were a number of other companies who incorperated a lean-burn mode in their economy cars (Mitsubishi comes to mind), but the use of it seems to have dropped off completely.  Is excessive NOx production to blame?

    • 0 avatar
      chaparral

      Lean-burn mostly faded away due to NOx emissions – they are far higher and the catalytic converter doesn’t have any CO or HC to reduce them with. The new direction appears to be higher compression, better combustion control, and stratified charging.

  • avatar
    chaparral

    I think the focus is on parallel-twins because they would be easier to package in a typical transverse-engine car than a vee or flat twin, and they could be cheaper to make as one head and cylinder barrel should be cheaper than two

  • avatar
    DenverMike

    Two identical EPA fuel ratings; The 2010 Explorer 2X4 with a 4.0 litre V6 and the 2010 F-150 Supercab 2X4 with the 4.6 V8. Guess which one is heavier by 500 lbs?

  • avatar
    DearS

    I sometimes wish I had the 190hp version of my car not the 170hp version I got, I’ve driven both. Still its a good deal of HP for my needs.

  • avatar
    niky

    Weight doesn’t play a huge role in EPA highway economy, drag does. Weight DOES play a role in city economy and in the real world, where you have to accelerate that weight.
     

     
    Cylinder count has nothing to do with engine longevity (except, of course, for harmonic imbalance… but that’s another story). It’s a misnomer to point at a hulking big agricultural engine and say that it’s more durable because it has more cylinders. It’s more durable because it’s big, heavy, heavily-built and very low-revving.
     

     
    Having driven 800cc cars, I can say that they’re not horrible in terms of get-up-and-go. A turbocharged 40 hp 800cc diesel in a microcar is bound to be quicker than a 1.8 liter Chevrolet Cruze with that slurry 6-speed automatic.

  • avatar
    Irish

    Light weight, low horsepower = E30.  I had a 1987 325 for a number of years.  That car was the most fun I ever had on 4 wheels.

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