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Diesel-Like Engine Could Boost Fuel Economy By 50%
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."
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.
None of us know everything. Therefore we're all naïve.
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.
People will just drive more to make up for the greater efficiency, and still whine about gas prices...
Can't wait to have my self-driving electric flying car by 2032.
I mean everything is moving over the next two decades to electric anyway.
Electric has a moving target to hit, just as it has for the last 100+ years. Batteries are not the only technology that can improve in the next two decades.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
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?
Seems a bit redundant really, I mean everything is moving over the next two decades to electric anyway.
Perhaps. It will depend on if we can figure out how to store electricity in the car less expensively then we can store the equivalent energy in a liquid fuel tank.
FTFA: Diesel is dirty and requires expensive exhaust systems.
It's probably inevitable-- it's just a question of when. Battery cost per kWh has been decreasing at around 10% per year, and gasoline is getting consistently more expensive. It seems incredibly unlikely that both of these would stop moving toward the crossover point.
Seems a bit redundant really, I mean everything is moving over the next two decades to electric anyway.
Until we see new power plants being built I am not so sure we will have a large scale transition to electrically powered vehicles. Various parts of our electrical grid are already pretty stressed out and seeing periodic brown outs and black outs. This could put a damper on large scale adoption of electric vehicles.
At least they won't rival the hybrid version of this engine.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
> I'm asking. Someone here knows, I bet.
Read the article. I'm begging you. Read it!
*Still* negative function...
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. 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.
The key distinction, as I'm aware, between diesel and gasoline is all about the ignition to begin with. In a gas engine, you create a spark to ignite a carefully mixed gas/air vapor. In a diesel, you don't need the spark, instead using sheer pressure from a much higher compression ratio. (this also leads to higher power per stroke, and therefore greater theoretical efficiency) Presumably they've found some way to reliably ignite gasoline without said spark, thus reaping the same compression ratio benefits or some such thing, I would guess.
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.
I don't think it's much of a moving target ... electric needs to reach a 600 mile range and charge in 10 minutes. That will make it an effective transportation alternative for all current automotive travel. It really doesn't need to get any better than that.
It's hard to see how electric can be beat in the long run. Even a 50% decrease in fuel use won't make gasoline fueling the cheaper choice.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
It's probably inevitable-- it's just a question of when. Battery cost per kWh has been decreasing at around 10% per year, and gasoline is getting consistently more expensive. It seems incredibly unlikely that both of these would stop moving toward the crossover point.
Gasoline engines have been keeping up with that 10% though. In 1998 the Ford Mustang GT with a 4.6L V8 had about 215hp. In 2011 the Mustang GT 5.0L V8 packed in 412hp. That's about 7% a year increase in power and a slight increase in mileage. It stands to reason if that extra efficiency was put towards more mpg instead of more power, that crossover point could be farther out than you think.
The good news is it's getting better on both fronts and fast!
long distances like the beach
If you're a long distance from a beach, you're doing it wrong.
It means "I approve of the above message which neatly encapsulates most of my feelings on the matter".
If you work out the math of various combustion-work cycles (see Otto Cycle, Diesel Cycle), and then take a look at how they are implemented in a typical gasoline or diesel engine, one of the things you immediately find is that efficiency is directly proportional to compression ratio. That is, the more you compress the air (or air-fuel mixture) before igniting the fuel, the better your efficiency.
Gasoline engines tend to be limited in their compression ratios, because if you compress the air-fuel mixture too much, it'll spontaneously ignite while the piston is on the upstroke, a phenomenon called pre-ignition or engine knock (because of how it sounds, I suppose). Diesel fuel burns a bit differently than gasoline, and diesel engines take advantage of spontaneous ignition: they purposefully have high compression ratios to heat up air in the cylinder, then inject the fuel when the piston is at/near the top of its stroke, where it immediately ignites. But diesel, as a fuel, has some practical downsides which has limited its more widespread adoption, primarily how cleanly it burns.
If, on the other hand, you could produce an gasoline engine that uses diesel-like compression ratios, and inject the gasoline at maximum compression, as a diesel engine does, you could have the best of both world: greater efficiency due to high compression ratio, cleaner running due to burning gasoline. But such an engine, for various technical reasons, has historically been difficult to achieve. Maybe these guys are really on to something.