GM to Build Light-Duty V-8 Diesel

Last year, Ford kicked off the light-duty diesel scramble when it said it would build a diesel F-150 in the not-too-distant future. Now GM has joined the fray, with plans to shoehorn a 4.5-liter diesel V-8 under the hoods of the Hummer H2 and light-duty 1500 versions of the GMC Sierra and Chevy Silverado. Expect them to arrive around 2010.

With space constraints dictated by its current lineup of pushrod gasoline engines, GM had to fit a square peg into a round hole, so to speak. The Duramax turbo-diesel sports a few space-saving tricks — among them exhaust portals that exit into the center of the “V,” not to the outside, as normally happens. The General says the engine will produce more than 310 hp and 520 pounds-feet of torque. Compare that to the chestiest gas V-8 in the Sierra 1500, which makes 400 hp and 415 pounds-feet of torque. Towing capacity will likely increase measurably over the Silverado and Sierra’s 10,500-pound maximum.

With decreased carbon dioxide and nitrogen oxide emissions, GM expects the Duramax to meet stringent emissions standards in all 50 states. Fuel efficiency should be up 25 percent versus a comparable gasoline engine, GM powertrain spokesman Tom Read said. We couldn’t find a gasoline V-8 in GM’s truck lineup that makes anywhere near 520 pounds-feet of torque, though, so we can’t predict any mpg.

Source: GM