General Motors has officially revealed the power specs for its new small-block V8 engines, which will debut in the 2027 Chevrolet Silverado and GMC Sierra. The updates position GM’s trucks ahead of Ford and Ram in raw horsepower, though not in overall output when turbocharged competitors are included.
The 6.6-liter L78 leads the lineup, producing 481 horsepower and 501 lb-ft of torque without forced induction—a figure that surpasses all other naturally aspirated V8s in its class. Even the smaller 5.7-liter L76 outpaces Ford’s 5.0-liter Coyote and Ram’s 5.7-liter Hemi, delivering 402 horsepower and 428 lb-ft of torque. Ford’s engine makes 400 horsepower, while Ram’s produces 395 horsepower.
GM achieved these gains through mechanical upgrades: larger pistons, a higher 12.5:1 compression ratio (up from 11.5:1 on the outgoing 6.2-liter), and a redesigned intake manifold with tuned runners. The 6.6-liter also features a 6-millimeter increase in piston stroke, while larger throttle diameters improve airflow. Despite these improvements, the 6.6-liter still trails Ram’s twin-turbo 3.0-liter inline-six, which outputs 540 horsepower and 521 lb-ft of torque.
Ford’s high-output EcoBoost V6 offers more torque (510 lb-ft) than GM’s V8, though with slightly less horsepower. GM’s Duramax diesel remains unchanged, holding steady at 305 horsepower and 495 lb-ft of torque. The 2.7-liter TurboMax four-cylinder, now the base engine, sees modest gains: 350 horsepower and 455 lb-ft of torque, up from 310 horsepower and 430 lb-ft last year.
GM’s new engines retain displacement on demand, a feature critics often cite as a necessity for meeting emissions standards. The company also dropped oil dipsticks in favor of a new coolant switch, a change that may frustrate some owners. While GM’s push to revive the V8 contrasts with rivals like Toyota (which no longer sells a V8 truck) and Ram (which briefly discontinued its V8 before reintroducing it), the move reflects a broader industry shift.
The 5.7-liter L76 also excels in towing, with a 13,700-pound rating in the Silverado and 13,500 pounds in the Sierra. GM’s focus on traditional engine architecture comes as hybrid and electric options grow in the market, positioning its trucks as a counterpoint to more fuel-efficient competitors.
