GM Finally Shares Power Figures for Its New Small-Block V-8s

General Motors revealed horsepower and torque ratings for its next-generation small-block V-8 engines, ending months of speculation about performance figures for the automaker's most anticipated powertrain refresh in years.

The 5.7-liter EcoTec3 V-8 produces 420 horsepower and 460 pound-feet of torque. The larger 6.6-liter variant generates 470 horsepower and 510 pound-feet of torque. Both engines pair with GM's 10-speed automatic transmission and will debut in the 2025 Chevrolet Silverado and GMC Sierra light-duty trucks launching later this year.

These figures represent a meaningful upgrade over the outgoing generation. The current 5.3-liter and 6.2-liter small-blocks produce 355 hp and 420 hp respectively, making the new 5.7-liter a gain of 65 horses and the 6.6-liter a 50-hp bump. Torque improvements track similarly across the board. GM engineered these engines with direct fuel injection, revised intake and exhaust systems, and optimized valve timing to extract additional output without requiring forced induction or hybrid assistance.

The timing matters. Ford's F-150 and Ram's 1500 dominate the truck market with strong V-8 performance and efficiency credentials. Ford's 5.0-liter Coyote produces 400 hp and 410 lb-ft in the F-150, while Ram's 5.7-liter HEMI makes 390 hp and 465 lb-ft in the 1500. GM's new numbers position the Silverado and Sierra competitively, particularly the 6.6-liter which tops both rivals in power output.

Fuel economy remains a critical battleground. GM claims the new engines will improve efficiency versus previous generations, though specific EPA ratings for the 2025 models remain forthcoming. The company emphasizes cylinder deactivation technology, which allows the engines to operate on fewer cylinders under light-load conditions, and advanced combustion chamber design to balance power and consumption.

The 6.6-liter engine carries historical weight. That displacement echoes GM's Duramax diesel line and represents the largest naturally aspirated engine in a modern light-duty truck segment increasingly pressured toward smaller, turbocharged units. By maintaining a large displacement V-8 option, GM signals commitment to customers who prioritize towing capacity and driving feel over meeting regulatory averages.

Truck buyers care about three things: towing capacity, acceleration, and fuel economy. These new engines address all three. The additional torque directly translates to better pulling power for trailers and payloads. Horsepower improvements deliver faster acceleration than before. The efficiency gains help owners manage fuel costs on long hauls.

GM faces tightening emissions standards and competitive pressure from electrification. The Silverado EV and GMC Sierra EV are coming, but not soon enough to abandon the gas truck market. These new V-8s represent the company's continued investment in traditional powertrains while transition timelines remain uncertain. The move buys GM time in its core market and keeps customers loyal through the early 2030s when full electrification becomes reality.

The new Silverado and Sierra demand strong performance credentials to justify their higher price tags versus predecessors. Horsepower numbers sell trucks. These specifications deliver a credible story to truck buyers eyeing Chevrolet and GMC against established competitors.