I was sent this article earlier today regarding General Motors demoing their new HCCI engines. While it is by no means a solution to the problem of vehicle emissions, it certainly is a cool step forward in engine technology.

GM looks to fuel savings; Automaker intends to improve mileage by up to 15 per cent

MILFORD, Mich. - General Motors says it intends to improve the mileage of its gasoline engines by up to 15 per cent by making them run more like diesel engines.

Although many automakers are pursuing the same strategy — notably Honda — GM became the first company Friday to publicly demonstrate the technology in running concept cars.

GM allowed the media to drive experimental HCCI engines installed in a Saturn Aura and an Opel Vectra built by its German subsidiary. Until now, most such experimental engines have been operated only in laboratories.

Both of GM’s HCCI cars operated flawlessly. But the technology is still too new and untried to be adapted to mass-market vehicles for another half decade, says the man shepherding GM’s search for new propulsion technologies. “This is not ready for prime time yet,” said Tom Stephens, group vice-president of powertrain for GM. “We don’t have a date pinned to it at all,” he said at the company’s proving grounds here, 80 km west of Detroit.

“But in my opinion it’s going to happen,” he said of mass market production of HCCI engines. “We wanted to lift the curtain a bit and show people what we’re working on here,” he said, explaining the presentation Friday.

GM’s HCCI engine is being developed with input from engineers in all half-dozen of its worldwide research labs, but mainly those in Michigan and Germany.

Called homogenous charge compression ignition, the system, which has been 30 years in development, enables gas engines to mimic key aspects of the diesel combustion cycle.

Specifically, the system uses high pressure and carefully controlled heat in cylinder exhaust gases to increase burn efficiency to levels only achieved in diesel engines until now.

Diesels are up to 30 per cent more efficient than gasoline engines. But they are more expensive to build and they create more emissions which are increasingly expensive to clean up as Western governments crack down on trace pollutants.

Those diesel shortcomings make HCCI an attractive and potentially profitable goal for the improvement of gasoline engines, GM officials say.

Stephens said GM will not be able to market HCCI technology until at least 2013, and possibly 2015. And he said it is too early to tell how much extra they will cost to produce.

But HCCI is not a pipe dream, he insisted. “The strides we’ve made just in the last nine months are incredible.” The major breakthrough, GM engineers at the event said, was a dramatic improvement in engine software which manages the split-second transition between normal operating modes and sparkless HCCI mode.

- The Windsor Star (Sat 25 Aug 2007)

In my third year at UofT, I had a course on combustion. We talked about HCCI briefly, the benefits of it etc. Its basically about the most fuel efficient internal-combustion stroke engine for burning regular gasoline. At the time, our professor mentioned that there was only one company (Honda, if my memory serves) that had a working prototype engine, and it was only large enough to power a small motorcycle.

Its interesting to see how quickly technology is moving ahead even as I am completing my education, particularly considering I just recently saw this video that talked about how “half of what [we] learn in [our] first year of study will be outdated by [our] third year of study.”

update: I found a really good article with an explanation of HCCI over at AutoblogGreen.