General Motors accidentally stole its own thunder by publishing the power figures of its new 6.6-liter V-8 Duramax turbo-diesel engine on one of its websites. Dubbed L5P, the engine is set to find its way under the hoods of the company’s heavy-duty trucks: the 2017 Chevrolet Silverado HD and the 2017 GMC Sierra HD.
GM, for its part, appears to have realized its mistake and has since taken the information off the GM Powertrain site. Nevertheless, the company left the figures up long enough for Truck Trend to grab a screenshot of the web page, which reveals that the L5P will sport a 16.0:1 compression ratio, have bore and stroke dimensions of 103 and 99 millimeters, and make 445 horsepower at 2800 rpm and a tremendous 910 lb-ft of torque at 1600 rpm. Those figures better those of the current LML 6.6-liter V-8 Duramax turbo-diesel engine by 48 horsepower and 145 lb-ft. Compared to crosstown rival Ford, GM’s L5P powerplant makes 5 more horsepower than the 2017 F-series Super Duty‘s 6.7-liter V-8 turbo-diesel engine, although the Ford, with 925 lb-ft of torque, tops the new Duramax’s leaked figure by 15 lb-ft.

Earlier this year, GM revealed that its diesel-powered Chevrolet Silverado HD and GMC Sierra HD models will get a new hood design with an integrated hood scoop for the 2017 model year. According to Chevrolet, this functional hood scoop is part of a new air-intake system that sucks in 60 percent of the air needed for combustion; the other 4...