2025 6.6l Duramax Turbo-Diesel V8 Engine Mpg. Complete information, specs, power and torque ratings on gm's 6.6l l5p v8 turbo diesel duramax engine used in the chevy silverado hd and gmc sierra hd. The 6.6l duramax l5p is the most recent generation of the duramax 6600 engine family and is found in 2017 to current chevrolet silverado, gmc sierra 2500 hd/3500 hd pickup and chassis cab trucks.
Despite tipping the scales at a staggering 8,269 pounds, the silverado 2500hd rocketed from. 10 best diesel engines (duramax vs cummins vs power stroke) duramax mpg for 5 most common trucks.