Chrysler Developing Engine That Burns Gasoline and Diesel
Chrysler and the U.S. Department of Energy are developing a radical prototype engine that burns a combination of gasoline and diesel fuels that could help Chrysler and other automakers meet future fuel economy targets, according to a presentation given by Chrysler during the DOE’s 2011 Merit Review in Washington D.C.
The small displacement 2.4-liter turbocharged four-cylinder multifuel engine promises up to a 25 percent improvement in city and highway fuel economy for a Chrysler minivan, compared to a 2009 4.0-liter V-6, while maintaining similar performance. That could mean that the new engine could reach 31 mpg on the highway in a Town & Country.
The 4.0-liter V-6 in the 2009 Chrysler minivan was rated 17/25 mpg city/highway and 251 horsepower and 259 pounds-feet of torque.
Until now, gasoline and diesel have been considered mutually exclusive automotive fuels because of their unique chemical and combustion properties. Gasoline engines use a so-called Otto combustion cycle, in which a combination of gas and air are mixed and compressed in an engine’s cylinders and ignited using a spark plug to produce power. Diesel engines follow the so-called diesel combustion cycle, where air is compressed to such a high degree that friction causes injected diesel fuel to ignite without a spark. Higher compression and greater energy density per gallon is what gives diesel about a 20 percent to 30 percent fuel economy advantage over gasoline.
Chrysler’s bi-fuel engine design calls for a three-valve head with two spark plugs, a side-mounted gasoline direct fuel injector and a centrally-positioned diesel injector. Two turbos – one high-pressure and one low-pressure – will provide two-stage turbocharging to meet boost requirements supporting a high compression ratio for power and fuel economy. Exhaust gas cooling and metered injection of diesel fuel will be used to control knock, or the premature detonation of the gasoline fuel-air mixture that can damage an engine under high compression loads.
“The addition (and timing) of diesel fuel has a significant impact on burn rate,” the presentation noted.
In this respect, Chrysler’s gasoline-diesel engine appears to be following a similar approach to Ford’s prototype bi-fuel engine, which used a mixture of gasoline and ethanol. The practical limitation of Ford’s engine would be the limited availability of ethanol in the real world, whereas diesel has widespread distribution across the U.S.
Both engines are also practically limited by the need for separate fuel tanks so the fuels aren’t mixed before combustion. In the real world, it’s not hard to imagine the extra hassle posed by filling up a vehicle at both the gas and diesel pumps.
Chrysler’s demonstration vehicle will show several other fuel-saving features, including shutting off fuel to the engine during vehicle braking, mild hybrid start-stop engine shutoff at stoplights and using waste engine heat to generate electricity to power some vehicle accessories instead of drawing accessory power from the engine.
The multifuel project is being funded with $30 million; Chrysler and its partners – including Delphi, FEV, Ohio State University and Argonne National Laboratory – are putting up $15.5 million, and the Department of Energy is putting up $14.5 million. It runs through April 2013.
The DOE published the full set of presentations from the 2011 Merit Review last week. We've asked Chrysler for comment about the project by e-mail but haven't heard back yet.
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Novelty idea at best...sad to see that so much $ has been spent on this :(
Things to make it production unlikely:
- both fuels are expensive;
- still dependent on fossil fuel;
- maintenance;
- extra fuel tank (which takes up space and weight);
- safety (2 fuel tanks);
- KISS: why doesn't Chrylser (or whoever) produce BOTH versions of minivan - a diesel version and a gasoline version? VW and Bimmer have been doing so quite successfully.
@AR,
the same was said about hybrids a decade ago.
i do agree that selling one or the other would be a simpler approach, but having the option of filling up and using either gas or deisel would be nice.
Interesting idea. Consumers will be able to buy whatever fuel is cheaper at the time of fill-up (gas or diesel).
I guess that to preserve passenger and cargo space there would be two smaller fuel tanks instead of one large one.
I'll believes it when I sees it.
@ cody,
I disagree 'bou the comparison with hybrid. The major complaint 'bou hybrid back then was that it was NEW (to N. America).
What's exactly is new 'bou this research here? A combo engine! A follow up question will be, "r there secondary requirement(s) for this combo engine to achieve its benefits?" (Answer is, "yes, diesel fuel."). Then the next question will be - do you (i.e. we) need a combo engine?
So the "benefit" of this research must be contributed by 2 factors - the engine, and a supply infrastructure. Only the 1st part is addressed. NOTHING on the 2nd part.
That's not the case with the hybrids or EVs.
Instead of wasting taxpayer's money on a research that's not really generating anything new, encourage
1. private fuel companies to have diesel pumps in most gas stations; and
2. have Chrylser offer both engines (instead of a combo).
Mind you, even if this vehicle is built, but no diesel pump infrastructure improvement, this "combo" vehicle will face the same road blocks that all current diesel vehicles are facing - difficult to get fuel. If the combo vehicle is to be driven via "gasoline" 99.99% of the time, then all fuel savings are just marketing talk. OTOH, when diesel pumps are everywhere, what's the need of the gasoline engine?
Do u c why this is a waste of taxpayer's money to research a "combo" engine?
P.S. The claimed mpg increase can easily be done by a diesel engine, so it's not like rocket science here. It's like saying, "ok diesel engine can achieve 25% better mileage. Now we've designed an engine that can run both diesel and gasoline. If you use diesel in this engine, you can achieve 25% better mileage. Woo-hoo. It's better than a standalone gasoline engine, and it's 'NEW' - now give us the grant for the research."
What's the advantage over just using a diesel engine?
@AR,
i disagree with your disagreement :-) i've been reading auto journalism for a couple decades now, and i distinctly remember repeated commentary about the complexity of hybrids, the added weight of lugging around the batteries, and reliability concerns.
however, as i said, i agree that going straight diesel would be a much easier approach. maybe there is a benefit that isn't outlined here over regular diesels. cleaner emissions? maybe it supports start/stop tech/etc better than a conventional diesel would.
i dunno, but i'm sure this combo engine will cost more than a regular diesel, which is already a little expensive. i think that would be the most significant hurdle. diesel is only hard to come by in certain parts of the country. it's as easy to find here in the southwest as gas.
taxpayer dollars are wasted on a lot of silly studies, but i don't necessarilly agree that this is one of them.
This engine is said to be able to meet Tier 2 Bin 2 emissions. The only thing cleaner would be buying an electric car (Tier 2 Bin 1 - ZEV). It appears to be able to do so without the extra expense and complexity of a pure diesel engine, which requires a diesel particulate filter and NOx trap.
Sad part is that such an engine was just patented a few weeks back that will not only burn gas and diesel; but also JP4, JP5, JP8 and Kerosene. However, try and get people to even look at it if you are not a big auto manufacturer! Nice part is it has fewer parts than a conventional engine and utilizes a single injector per cylinder and fuels can be changed while running or mixed; the engine does not care!
Good concept, so we can use both Ethanol (E10, E15, E85) or Biodiesel (B2, B10, B20) wherever available.
If I understand correctly, this engine burns diesel & gasoline _SIMULTANEOUSLY_ using several clever tricks to increase the efficiency of burning the less expensive gasoline. Read carefully - most obvious statement is "... it’s not hard to imagine the extra hassle posed by filling up a vehicle at both the gas and diesel pumps."
Um they already came out with a multi fuel engine so chrysler can go suck it because its already been done and they're just trying to steal other peoples ideas.
This isn't a new concept.
When I served in Viet Nam in 1967 our Deuce-an-a-half trucks all had inline six-cylinder engines that ran on diesel and on gas, or anything in between.
At that time, out in the field, we ran mostly diesel but when we didn't have any, we filled up with gas intended for the Jeeps.
Oh, yeah, and the engines had both sparkplugs AND glowplugs.
Maybe Fiatsler should break out some of those old engineering books used to design and build those military engines.
Good for the times when you can't find a station that sells diesel, or you don't trust the quality of the diesel fuel that is being sold.
Why is this news? Our 1992 Dodge Caravan had a radical prototype engine that burned a combination of gasoline and OIL at only 30,000 miles!