What if you could have the performance of a 4.0 liter V6, while returning the fuel economy of an inline four? Chyrsler is working with the Department of Energy on just such an engine, and it will use both gasoline and diesel to achieve these performance targets. It won’t burn the two fuels independently, so running out of gas (or diesel, presumably) will still leave you stranded. Instead, the engine burns the two fuels simultaneously to achieve both superior performance and fuel economy.
The engine is primarily a gas-burner that utilizes high compression and twin turbos to make reasonable power from a small displacement. Diesel is injected into the combustion chamber to control preignition, which allows the engine to run higher compression than pump gas normally allows. As a result, Chrysler claims comparable performance with a 25 percent improvement in fuel economy compared to their 2009 model year 4.0-liter V6. That translates into 31 mpg on the highway in a Town & Country minivan, but a smaller, lighter vehicle could see even bigger fuel economy improvements.
Chrysler isn’t the first automaker to undertake a multi-fuel engine project. Ford is working on a multi-fuel engine that uses both gasoline and ethanol, but there currently isn’t an infrastructure in place to support such a design in the real world. Where, exactly, would you buy ten gallons of ethanol? Diesel is commonly available from coast to coast, but both designs suffer from the same design drawback: multi-fuel engines require two separate fuel tanks and fuel systems, and they assume that drivers will never inadvertently mix fuels.
Since the engine is only in the design phase, Chrysler has time to sort out the bugs. I like the possibilities that such a design presents, because it shows that horsepower can coexist with fuel economy. Maybe the future for us horsepower junkies isn’t as bleak as we thought.
Source: Kicking Tires