General Motors will offer this new V8 diesel engine on many light-duty trucks and SUVs, starting with the Chevy Silverado and GMC Sierra in 2010. (Photo courtesy of General Motors Corporation)
PONTIAC, Michigan — General Motors is readying a V8 diesel engine that the company will offer for light-duty trucks, starting in 2010 with its Chevrolet Silverado and GMC Sierra.
The DuraMax 4.5-liter engine makes 310 horsepower and 520 pound-feet of torque and is expected to serve up fuel economy numbers 25 percent higher than comparable gasoline engines. GM says the narrow V-angle block allows the diesel to fit in any hole that currently accommodates a small-block V8 gas engine. That leaves GM with plenty of options for offering the diesel in other models such as the Chevrolet Tahoe and Suburban. Conceivably, the new DuraMax could even be shoehorned into a Corvette — but don't bank on seeing that anytime soon.
The engine uses dual overhead cams and four valves per cylinder. Exhaust manifolds are integrated into the cylinder heads, while the intake manifolds are formed as part of the cam cover. A variable-vane turbocharger compresses intake air before it reaches the cylinder, and a 29,000-psi fuel system delivers the diesel.
"By using integral cylinder head exhaust manifolds, integral cam cover intake manifolds and a narrow cylinder block, designers saved space and reduced the engine's weight. And because the engine makes more efficient use of heat, fuel economy and performance are enhanced, and noise and emissions are reduced," said Gary Arvan, chief engineer for the 4.5-liter V8 diesel.
To tackle the tough new Tier 2 Bin 5 emissions standards, the DuraMax uses a particulate filter and selective catalytic converter that captures nitrogen-based emissions to burn them off later during an engine cycle.
What this means to you: Whether you want low-end torque or higher fuel economy, diesels definitely make sense in this application. — Eric Tingwall, Correspondent