GM Quietly Releases, Then Deletes 2017 6.6L L5P Duramax Turbo Diesel Engine Specs by Michael Accardi September 26, 2016September 26, 2016 Share Comments Thread A document containing official horsepower and torque numbers for GM’s brand new 6.6L V8 Duramax turbo-diesel was found buried on the GM Powertrain website–before the company quickly deleted it. GM’s new 2017 heavy duty pickup trucks will wade into the nuclear torque war with a whopping 910 lb-ft of twist, with peak torque coming on at just 1,600 RPM. Horsepower is up by nearly 50 to 445 hp at 2,800 RPM– thanks in part to a new turbo design–while the 103 mm bore x 99 mm stroke remains identical. The L5P’s 910 lb-ft of torque puts it middle of the road between the Ford Super Duty’s 925 lb-ft and the Cummins Ram at 900 lb-ft, however, its 445 hp rating leaves GM with the horsepower crown versus Ram’s 385 hp and Ford’s 440 hp. Thew new L5P Duramax is slotted for production at the GM-Isuzu plant in Moraine, Ohio and will see action in both Heavy Duty Silverado and Sierra twins. The accidental release comes just days before GM’s new HD trucks are set to officially debut at the 2016 State Fair of Texas, where we should receive transmission and towing specs.