Clean or Efficient? An Engine Goes for ‘Both of the Above’

[Derek77]

NY Times: Clean or Efficient? An Engine Goes for ‘Both of the Above’

FROM the outside, the dark blue Saturn Aura accelerating to a steady 50 miles an hour on the high-bank oval here at General Motors’ proving grounds looked altogether unremarkable.

In fact, it was not much to look at under the hood either, despite an experimental engine using a method of burning gasoline that may prove to be the next major advance in fuel economy and emissions control. Only a couple of stray electrical connectors hinted at the differences distinguishing this engineering prototype from thousands of other Auras on road.

[RJB]

You will see HCCI in diesels soon too. This process of combustion has been in the works in some form or another for quite some time.

[loki]

The 2.2-liter engine in the test Aura is based on the G.M. Ecotec four-cylinder; a 2.4-liter version of this engine is available in the Aura for 2008. G.M. rates the H.C.C.I. engine at 180 horsepower and 170 pound-feet of torque of torque; by comparison, the ’08 Aura engine makes 164 horsepower and 159 pound-feet, and is rated at 22 miles a gallon in town and 30 on the highway.

G.M. would not give fuel economy figures for the H.C.C.I engine beyond the expectation of a 15 percent improvement in mileage.

so about 25 city and 34 highway and best inclass hp

be great for this type of engine to go into the volt too.

i bet the job they have is frustrating, but awesome too.