General Motors unveils new 8.3-liter Duramax V8 diesel engine

General Motors has unveiled a new 8.3-liter Duramax V8 diesel engine, internally codenamed ‘Mongoose’, designed for the Chevrolet Silverado HD and GMC Sierra HD heavy-duty pickup trucks. This new engine represents a significant departure from the previous 6.6-liter unit, featuring a completely new design with a graphite-reinforced cast iron block, forged crankshafts, connecting rods, and steel pistons.

The new powerplant is expected to deliver 563 horsepower and 1,668 Nm of torque, marking a substantial increase in performance over the outgoing model. This power boost aims to enhance towing capacities, with maximum towing weights reaching between 9,072 kg and 17,237 kg depending on the configuration.

The announcement includes a clear competitive stance against Ford’s 6.7L Power Stroke engine, which carries the internal code ‘Scorpion’. GM’s choice of the ‘Mongoose’ moniker is a direct marketing provocation, referencing the predator known for hunting scorpions. The new engines are slated to arrive with 2027 model year vehicles, with the first units expected to reach customers by late 2026.