GM Dishes More on Light-Duty Duramax Diesel

In spite of the current sales slump in the full-size truck market, each of Detroit’s automakers are in a race to produce a diesel-powered light-duty pickup. None have come to market as of yet, but thanks to a new release, we now know more about General Motors’ upcoming 4.5-liter Duramax turbo-diesel V-8.

Slated to bow in Chevrolet Silverado and GMC Sierra pickups in the 2010 model year, the diesel motor is expected to produce around 310 horsepower and 520 lb-ft of torque, all while delivering a 25-percent improvement in fuel economy compared to a gasoline motor of similar power. On that note, the current 5.3-liter V-8 found in the Silverado/Sierra twins puts out a similar figure of 315 horsepower, but its torque figure – 338 lb-ft – falls way short of the Duramax.

Having that kind of power in a light-duty truck isn’t all that common, but the compact size of the 4.5-liter allows GM to package the new diesel into smaller vehicles. The tight angle of the V-block, coupled with integral exhaust manifolds and some wicked turbocharger packaging, allows the motor to be the same size as a normal small-block V-8. With that in mind, we could easily see this motor being applied in other truck and SUV applications that make use of GM’s current 5.3- or 6.0-liter V-8s, although the General hasn’t commented on such fantasies.

On the emissions front, the 4.5-liter will be GM’s first foray into a selective catalytic reduction system, allowing the motor to be 50-state compliant. Compared to current diesels, GM officials say the motor offers a 13-percent cut in carbon dioxide and 90-percent decrease in nitrous oxide output.