From Motortrend

General Motors is readying a new 4.5-liter V-8 Duramax turbodiesel engine for use first in the 2010 Chevrolet Silverado and GMC Sierra light duty trucks. The new engine is relatively compact thanks to integral aluminum cylinder head exhaust manifolds, integral cam cover intake manifolds, and a narrow V-angle block. As a result, GM says, the engine can fit in the same space as a small-block V-8 gas engine.
2008 Chevrolet Silverado

The 4.5-liter diesel will meet LEV2 emissions standards and be sellable in all 50 states. Producing 310 horsepower and 520 lb-ft of torque, GM says the engine will achieve fuel efficiency 25 percent better than comparable gas engines and is the first GM engine to employ a selective catalytic reduction NOx after-treatment system with a diesel particulate filter. Compared to “many diesel vehicles today,” GM says, the new engine reduces CO2 emissions by 13 percent as well as a 90 percent reduction in particulates and NOx.

The engine has a variable-vane turbocharger with intercooling and a compacted graphite iron cylinder block which helps make the engine strong and light, compared to one composed of aluminum or grey cast iron. If buyers are willing to pay the slight premium for new diesel technology (not to mention the diesel premium at the pump), we wouldn’t be surprised to see diesel-powered Chevy Silverados and GMC Sierras make up a larger share of GM’s shrinking fullsize truck and SUV production.