GM's Gen 6 6.6L V-8 Brings Power, Efficiency—and a Brand-New Oil System—to Silverado/Sierra

GM’s 6.6-liter Gen 6 small-block V-8 (L78) debuts in the 2027 Silverado/Sierra, delivering 481 hp and 501 lb-ft to become the most powerful naturally aspirated pickup, aided by increased displacement, a larger throttle body, a new intake, and a 12.5:1 compression; it uses a dual direct/port fuel system for efficiency and emissions and features a completely new oiling architecture with a pan-integrated cooler and a variable-displacement oil pump—plus a digital oil level sensor in the cabin because there’s no dipstick; GM backs the engine with a 10-year/150,000-mile warranty. Availability at launch includes the 6.6L alongside a smaller 5.7L V-8, upgraded four-cylinder turbo, and refreshed Duramax diesel.