DETROIT - The diesel engine is about to get a starring role at General Motors.
GM is building a new V-8 diesel for light-duty trucks and SUVs that is expected to meet Federal Tier 2 and California emissions standards and be available in all 50 states as early as 2010.
At a press event last week at GM's Milford, Mich., proving grounds, Charles Freese, GM's executive director of diesel engineering, said the new engine should boost the fuel economy gain of a vehicle such as the Chevrolet Tahoe by about 25 percent. That would enable the 5,000-pound SUV to get around 26 mpg on the highway.
Freese would not give the displacement of the engine. He did say it is larger than the 3.0-liter but smaller than the current 6.6-liter Duramax diesel used in heavy-duty versions of the Chevrolet Silverado and GMC Sierra pickups.
The new engine is designed to fit in the space of GM's current 5.3-liter gasoline engine. Engineers installed an early hand-built prototype of the engine in a blue Buick Rainier SUV and let journalists test it on the proving grounds.
There was no way to tell the engine was a diesel unless you put your ear near the hood. It ran as smoothly and quietly as a gasoline engine. The test engine is rated at 330 hp and develops 620 pounds-feet of torque.
The engine has double-overhead cams and four-valves per cylinder and uses a selective catalytic reduction or urea injection system to clean the exhaust.
You may e-mail Richard Truett at [email protected]