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Diesel-Like Engine Could Boost Fuel Economy By 50% 721

Posted by Soulskill
from the then-they-can-justify-charging-us-double-for-gas dept.
bonch writes "Autoparts manufacturer Delphi has developed a diesel-like ignition engine running on gasoline, providing a potential 50 percent efficiency improvement over existing gas-powered engines. Engineers have long sought to run diesel-like engines on gasoline for its higher efficiency and low emissions. Delphi's engine, using a technique called gasoline-direct-injection compression ignition, could rival the performance of hybrid automobiles at a cheaper cost."
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Diesel-Like Engine Could Boost Fuel Economy By 50%

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  • by krept (697623) on Friday May 18, 2012 @01:04PM (#40042831)
    WOOHOOO!!!
    I don't really care about the karma here, but there's been so much bad news lately this is rather refreshing.
    I'll let the critics speak and explain why this is not as good as it sounds, but FTS it's inspiring.
    • by Anonymous Coward on Friday May 18, 2012 @01:32PM (#40043231)

      It is niether a bad idea nor magic. By pulsing injections they make the combustion behave closer to the Carnot cycle ideal, which is more efficient than the Otto cycle.

      That aside, I have my doubts about the 50% improvement. And diesels are already closer to the Carnot cycle so you could say they are effectively running a diesel on gasoline.

      One important benefit it could have over diesels though, is that diesel burns fairly slowly compared to gasoline - which is the reason why diesels rarely rev above 5000 or so. If they manage to get diesel-type efficiency but with faster-burning gasoline, it could result in an engine that feels and behaves like a gasoline engine but has the mileage of a diesel. That would be nice.

      • by tomhath (637240) on Friday May 18, 2012 @01:43PM (#40043383)

        I have my doubts about the 50% improvement.

        Careful reading reveals that your doubt is well placed, but you misread their claim:

        technology that could improve the fuel economy of gas-powered cars by 50 percent...Diesel engines are 40 to 45 percent efficient in using the energy in fuel to propel a vehicle, compared to roughly 30 percent efficiency for gasoline engines.

        So all they really claim is that a diesel engine that runs on gasoline has roughly the same efficiency as a fuel-oil powered diesel.

    • by Grishnakh (216268)

      It sounds all nice, but I see an article about some new "miracle" engine technology or configuration that claims to deliver enormous gains in efficiency every year or so.

      However, there is one thing that really stands out about this one: the claim is being made by Delphi, which is a very large company and the main supplier to GM (not long ago, it was actually part of GM). Usually, these "new engine" press releases are from some tiny 2-person company no one's ever heard of, and never hears from again after t

  • by Anonymous Coward on Friday May 18, 2012 @01:06PM (#40042841)

    From what I understand, the major challenge of combustion without a spark plug for gasoline is preignition. High pressure direct injection allows normal spark-plug motors to run at higher compression ratios with lower chance of knock (preignition), so that was part of it, but I wonder what other fabulous tech was used to get this to be feasibly production ready. Very cool.

    • by wile_e_wonka (934864) on Friday May 18, 2012 @01:41PM (#40043371)

      All questions answered (from TFA):

      [T]he researchers found that if they injected the gasoline in three precisely timed bursts, they could avoid the too-rapid combustion that's made some previous experimental engines too noisy. At the same time, they could burn the fuel faster than in conventional gasoline engines, which is necessary for getting the most out of the fuel.

      They used other strategies to help the engine perform well at extreme loads. For example, when the engine has just been started or is running at very low speeds, the temperatures in the combustion chamber can be too low to achieve combustion ignition. Under these conditions, the researchers directed exhaust gases into the combustion chamber to warm it up and facilitate combustion.

      Mark Sellnau, engineering manager of advanced powertrain technology at Delphi Powertrain, says the engine could be paired with a battery pack and electric motor, as in hybrid cars, to improve efficiency still more, although he notes that it's not clear whether doing that would be worth the added cost.

    • by icebike (68054) * on Friday May 18, 2012 @01:55PM (#40043555)

      Well, as the article pointed out, they are using a much finer grained control of the injection precisely to control knock, injecting fuel in up to three shorter bursts.

      This also allows them to space those bursts at precise times during the power stroke, such as when the piston is going down, and the expansion of the initial burst of fuel is losing effectiveness due to combustion chamber expansion reducing the instantaneous pressure. Adding a burst of fuel at that point gets you extra power at what would otherwise be the downward (backside) of the power curve.

      Previous approaches to this were attempted with variable valve actuation [osu.edu], (essentially getting rid of the cam shaft and using other means of controlling valves more precisely). Costly, but effective.

      This approach (precisely controlling fuel delivery) allows you to shape the combustion profile to the continuously varying cylinder volume and perhaps adjusting that for changes in engine loading as well.

  • Jevons Paradox (Score:4, Insightful)

    by Anonymous Coward on Friday May 18, 2012 @01:07PM (#40042851)

    People will just drive more to make up for the greater efficiency, and still whine about gas prices...

    • by Anonymous Coward on Friday May 18, 2012 @01:16PM (#40042957)

      There's limits to this effect. My florescent lightbulb on my desk lamp is 400% more efficient than the incandescent bulb it replaced, but that doesn't make me sit at my desk 4 times longer.

      • by Anonymous Coward on Friday May 18, 2012 @01:59PM (#40043611)

        ...but that doesn't make me sit at my desk 4 times longer.

        I couldn't log into the Diablo III servers either. Had to move to the couch and find the damn remote.

    • Re:Jevons Paradox (Score:5, Insightful)

      by NeutronCowboy (896098) on Friday May 18, 2012 @01:24PM (#40043081)

      Err, no. Driving has some significant extra costs that aren't captured by how much I spend on gas in a week: the time I sit in the car, being utterly unproductive. For some - specifically for those who drive for fun or work - this might lead to a zero reduction in gas costs. But it will reduce it for a whole lot of other people.

    • Re:Jevons Paradox (Score:4, Insightful)

      by squiggleslash (241428) on Friday May 18, 2012 @01:39PM (#40043317) Homepage Journal

      Why the hell would anyone drive more just because the price of fuel is lower? People drive largely because they have to, not because they want to.

      I would insert an analogy here, but the fact of the matter is I have several thousand in mind right now, and it's proving impossible to choose between them.

  • From a buffoon (Score:4, Insightful)

    by Anonymous Coward on Friday May 18, 2012 @01:08PM (#40042865)

    What keeps diesel engines from becoming a standard in the US? I know regulations nearly disappeared them from the market, but that was for environmental reasons, which are the very reasons why diesel cars are attractive. While in Europe it is not outside the norm, here it seems like you are committing a crime if you run a diesel engine.

    Also - since diesel engines are so efficient and all - what stops them from making a hybrid car that benefits from the even greater efficiency of diesel? or this new type of diesel like gas engine for that matter?

    • Re: (Score:3, Informative)

      by Anonymous Coward

      There are diesel hybrids being sold right now in Europe. Also, Audi will probably win this years 24h of Le Mans with a diesel hybrid (Audi R18 TDI e-tron quattro, google it), which will be a first. That is bound to attract a lot of notoriety and drive more manufacturers to employ that technology onto its roadgoing cars.

    • Re:From a buffoon (Score:5, Insightful)

      by Nutria (679911) on Friday May 18, 2012 @01:21PM (#40043033)

      High fuel taxes on diesel, because 18-wheelers are business assets and gov't loves to tax business, since it's hidden from the consumer.

      • Re:From a buffoon (Score:5, Insightful)

        by Waffle Iron (339739) on Friday May 18, 2012 @01:49PM (#40043481)

        High fuel taxes on diesel, because 18-wheelers are business assets and gov't loves to tax business, since it's hidden from the consumer.

        Since big rigs account for about 99% of road damage, the truck companies are still coming out ahead of car drivers on fuel tax paid vs. government entitlements received.

      • by bhtooefr (649901)

        Actually, that's not it at all. 18-wheelers are HEAVILY subsidized, even with the slightly higher fuel taxes on diesel.

        To break even on road tax, the taxes on 18-wheelers would be based on weight and mileage, and would be so much higher than car road tax, that it would literally cost more to tax the cars than the revenue from taxing the cars.

        I wrote up a blog post about that: http://bhtooefr.org/blog/2012/03/19/why-long-haul-trucking-is-an-awful-idea-and-rail-is-far-better-for-long-distance-transport/ [bhtooefr.org]

    • by BagOBones (574735)

      In Canada diesel fuel used to be cheaper than regular fuel due to less refinement, however taxes now make it more expensive than regular off setting the fuel efficiency so no one wants them.

    • Re:From a buffoon (Score:4, Interesting)

      by Idbar (1034346) on Friday May 18, 2012 @01:23PM (#40043057)
      I've been asking this forever! If Diesel engines have better torque, why not using them in hybrids as power plant (in a similar way Direct UPSs work). After all, most power plants I know are diesel, not gasoline.
    • Re:From a buffoon (Score:5, Informative)

      by demonbug (309515) on Friday May 18, 2012 @01:23PM (#40043063) Journal

      What keeps diesel engines from becoming a standard in the US? I know regulations nearly disappeared them from the market, but that was for environmental reasons, which are the very reasons why diesel cars are attractive. While in Europe it is not outside the norm, here it seems like you are committing a crime if you run a diesel engine.

      Also - since diesel engines are so efficient and all - what stops them from making a hybrid car that benefits from the even greater efficiency of diesel? or this new type of diesel like gas engine for that matter?

      Many reasons diesel hasn't been popular in the U.S. One reason is environmental concerns - at least in the north east U.S. and California, our emissions standards, particularly for particulates and sulfur compounds, are much stricter than Europe. A second reason is that people tend to buy cars based on horsepower, and diesels lag there. Third, lots of people have bad memories of noisy, smelly diesel engines from the 80's. Fourth, diesels cost more. All that said, they are making a comeback with the newer offerings from VW and BMW (and Mercedes?).

      I believe the reason diesels haven't been seen in hybrids is a combination of several factors. One, they are heavier than gasoline engines which in a hybrid already facing weight issues due to batteries could be a problem. Second, they are more expensive than gasoline engines, and again hybrids already face a cost problem. Third, the efficiency gains using gasoline engines have been sufficient to set them significantly apart from most non-hybrid cars, so the additional mileage you might get from using a diesel instead isn't worth the additional cost and weight.

    • Diesel is more effecient and produces less carbon overall, but is does produce nasty Nitrogen and Sulphur compounds. Until the recent decade there was no way to effectively filter and dispose them off. But now we have means to 'burn' them off into relatively safer compounds, and there is pretty much no reason to opt for diesel.

    • Installed industrial base and public perception are the main culprits, I guess.

      The production, distribution and consumption chain is geared towards gasoline, making diesel a less safe option as you can't be sure you'll be able to refill at any station.

      North Americans are also used to equate V6 and V8 with power (although this is changing with the latest small turbo-4s such as EcoBoost), where the car diesel engines are most often geared for economy rather than performance (unless you look at BMW *35d series

    • by cpu6502 (1960974)

      >>>What keeps diesel engines from becoming a standard in the US?

      The diesel cars introduced during the 70s/80s fuel crisis were crap, and now they have a reputation for being smelly and unreliable even though that's not really true anymore. Modern diesels are LEV qualified.

      >>>what stops them from making a hybrid car that benefits from the even greater efficiency of diesel?

      Nothing. Several companies have built prototypes over the years (example: An 80mpg Dodge Intrepid), but they've all de

    • by Solandri (704621)
      I had a long reply written up but lost it in a browser crash. So here's the short version. You don't want to convert all gasoline cars to diesel. You want there to be a healthy mix of the two.

      When you refine crude oil, it distills out into a variety of substances, - kerosene, gasoline, diesel, fuel oil, tar, waxes, etc. Ideal case is when your gasoline and diesel use exactly matches the proportions of those which distil out.

      The next-ideal case is when you use more gasoline than distils out. Gasoli
    • While there are advantages to a diesel engine, there are also disadvantages.

      I tool around in my little 1.3L turbodiesel hatchback, rarely straying above 2000rpm, getting about 54mpg with hardly any effort. The greater torque compared to a similar-sized gasoline engine is very nice for daily driving, it makes overtaking less stressful and let's me drive along in town at ~35 in 4th gear at 1500-1600 rpms or so. Bigger diesels can even drive around town in 5th or 6th gear, no problem.

      Now, drawbacks. There are

  • by wonkavader (605434) on Friday May 18, 2012 @01:12PM (#40042915)

    OK, yes, this makes a gasoline engine more efficient by emulating a diesel. Why not just go with diesel, then?

    Is there more energy density in gasoline? Is it cheaper to produce? Or is this just about gasoline being more widely available and consumers being more comfortable with it?

    I'm asking. Someone here knows, I bet.

    • by Anonymous Coward on Friday May 18, 2012 @01:15PM (#40042943)

      FTFA: Diesel is dirty and requires expensive exhaust systems.

      • by MtViewGuy (197597)

        You are correct. To clean up a turbodiesel engine, you need a combination of diesel particulate filters and urea liquid injection into the exhaust stream to chemically "break up" the NOx gases to a simpler form that is easily removed by standard catalytic converters. Developed originally by Mercedes-Benz under trademark name "BlueTec," it's a pretty expensive system of exhaust emission control, hence the reason why such systems have been limited to higher-end turbodiesel models.

    • Re: (Score:2, Redundant)

      TFA: "... But diesel engines are dirty and require expensive exhaust-treatment technology to meet emissions regulations."
    • by nigelo (30096) on Friday May 18, 2012 @01:18PM (#40042989)

      > I'm asking. Someone here knows, I bet.

      Read the article. I'm begging you. Read it!

    • by Nikademus (631739) *

      Gasoline is more efficient than oil in the same conditions. The problem is (or was in this case), the 2 types of engines cannot run in the same conditions, you can get more compression ratios with oil and it needs it to burn. Previous attempts at making a gasoline engine with a very high compression ratio like the diesel one resulted in explosions or melted engines.
      Also, when you produce 1 liter of oil, you also produce some gasoline (even more than a liter if I recall correctly). So both should still coexi

  • Let's face it, economic social justice requires us to enable the billion+ people around the world today who do not have access to personal transportation (like we do) to gain that access. Anything else is unjust. Breakthroughs like this one are a step in that direction.
    • by Aquitaine (102097) <`sam' `at' `iamsam.org'> on Friday May 18, 2012 @01:23PM (#40043059) Homepage

      You keep using that word "justice." I do not think it means what you think it means.

      If by "economic social justice" you mean "ways I believe that I should spend your money" and if by "unjust" you mean "bad because it is not how I would allocate your resources," then maybe.

      But "justice" is the application of law to achieve a fair, reasonable, and consistent outcome. If your neighbor gets fined $100 for leaving trash on the street and you do the same thing but don't get fined, that's unjust.

      Enabling or subsidizing somebody else to have access to something that they do not currently have may be altruistic or philanthropic and it may even be a good idea, but it's got nothing to do with justice. "Social Justice" might have meant something once, but it's been hijacked in pursuit of so many agendas (because everybody likes Justice, right?!?) that it's about as meaningful as the names of laws, where you regularly see things like "The American Equal Opportunity And High Paying Jobs For Everyone Act" that does nothing like what the title says.

      • by hey! (33014)

        If by "economic social justice" you mean "ways I believe that I should spend your money" and if by "unjust" you mean "bad because it is not how I would allocate your resources," then maybe.

        Straw man. In the context of environmental protection, "justice" would mean things that the air people in poor neighborhoods would be nearly as clean as the air people in wealthy suburbs breathe.

        I'll give you another example. Some years ago there was a proposal to establish airline service at an air force base which for decades has been a research center that hasn't supported combat aircraft since the 50s. I remember walking into the break room at work and hearing two people who happened to live in a very

  • by davidwr (791652) on Friday May 18, 2012 @01:17PM (#40042985) Homepage Journal

    At least they won't rival the hybrid version of this engine.

  • by takaitra (1441033) on Friday May 18, 2012 @01:18PM (#40042991)
    Don't forget that, when considering the extra mining and transportation of rare earth metals required to build a hybrid car, its overall environmental impact might not be any better than a conventional gasoline engine [suite101.com]. My choice would be to buy a gasoline powered car with 50% improved efficiency over hybrid--at least until battery technology (and China's environmental policies!) improve.
  • I seem to remember hearing about a type of engine from the 1930's that was designed to run this way. The name escapes me, but basically, fuel was sucked in, and then the engine (once at operating temperature) would run off of pre-ignition, which allowed it to run using much more fuel. The problem with the engine back then was that the pre-ignition was somewhat unpredictable which made the engines extremely unreliable at best. Pre-ignition is something that can kill modern engines fairly quickly. It means th
  • by sl4shd0rk (755837) on Friday May 18, 2012 @01:29PM (#40043155)

    Gasoline. Because we still have glaciers.

  • by geekoid (135745) <dadinportland&yahoo,com> on Friday May 18, 2012 @01:31PM (#40043191) Homepage Journal

    Hybrid will use this as well.

    It's good thing, hope it pans out.

  • by na1led (1030470) on Friday May 18, 2012 @01:44PM (#40043403)
    This is nothing new really. They had similar technology back in the 70's but it was never pursued much because people preferred driving BIG GAS HOGS. 1975 Honda Civic had a similar type of technology - http://en.wikipedia.org/wiki/CVCC [wikipedia.org]. I owned one of these cars. It was small, an automatic without the D (drive), just speeds 1 and 2. Wish I still had the car today.
    • Again read the article- likewise fuel injection and 4 valve OHC has been around since the 40's but it has been a matter of getting manufacturing and engine management costs to a point where it could economically feasible to sell them to consumers.

      Your CVCC example is somewhat related but a far cry from a direct injected gas motor with controlled dieseling.

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