A Link Between High-Performance Race Cars and School Buses?

Perhaps it's all a bit premature, but an intriguing concept was reported last week on Wired.com.

Ilmor Engineering of the U.K. and Plymouth, Mich., owned by Roger Penske, may be known to some as a leading manufacturer of engines for Formula-1 and IndyCar racing as well as high-performance marine racing. But the 25-year-old company is also hoping to revolutionize the combustion engine market amid the global green wave of hybrids. electrics and alternative fuels. It recently introduced a prototype gasoline five-stroke engine, a new take on its 125-year-old, four-stroke cousin.

It's an interesting development in a time when increased fuel economy and reduced emissions are on everyone's list of talking points. But the Ilmor five-stroke actually promises comparable output and fuel efficiency as a diesel engine minus 20 percent of a diesel engine's weight and the nitrogen oxides and particulate matter. Ilmor also says the five-stroke is ready for tests and could be used in conjunction with a hybrid drive.

Says Wired:

...the technology is '100% conventional' [according to Ilmor] and doesn’t require any new manufacturing techniques.

Ilmor says that the prototype five-stroke engine, based on a design by Gerhard Schmitz, has an overall expansion ratio “approaching that of a diesel engine – in the region of 14.5:1.” Along with its light weight and relatively high output, the extra work done in the low pressure (LP) cylinder provides for better fuel economy.

“Running of the concept engine has produced impressive fuel consumption readings over a very wide operating range,” the company said in a statement. “This is because at the onset of knock a greater percentage of work can be extracted in the LP cylinder, giving a degree of self compensation.”