GM keeps V8 and diesel power for 2027 Silverado and Sierra with two new Small Block engines
General Motors is holding onto combustion choices for its redesigned half-ton trucks, confirming two new V8s and a returning diesel inside a four-engine lineup.
- 2 (L76 5.7L, L78 6.6L)
- 305 hp, 495 lb-ft
- 34 gallons (129 liters)
- 27 mpg (2WD)
What Happened
General Motors has introduced two new V8 engines built on the sixth generation of its Small Block architecture. The L76 displaces 5.7 liters and the L78 displaces 6.6 liters, and both are aimed at the next-generation light-duty pickups from Chevrolet and GMC, the 2027 Silverado 1500 and Sierra 1500. GM says the pair lifts capability and performance for full-size truck customers. They arrive when those trucks launch later this year, with pricing still to be announced.
- New L76 5.7L V8 (sixth-generation Small Block)
- New L78 6.6L V8 (sixth-generation Small Block)
- Enhanced TurboMax
- Duramax 3.0L turbo-diesel, offered as an option
305 hp / 495 lb-ft
The segment-exclusive diesel returns for the 2027 trucks, with plenty of low-end torque for towing and long-distance driving.
Alongside the returning diesel, GM lists revised internals and sensors: pistons, turbo vanes, a next-generation NOx sensor, sealing changes and injector protection against corrosion, plus a revised DEF level indicator. GM says these changes are meant to shore up reliability and buyer confidence. Every 2027 light-duty engine shifts through a 10-speed automatic. A 34-gallon (129-liter) tank can be added to either new V8, and with the diesel GM estimates more than 900 miles of highway driving at 27 mpg in two-wheel drive.
over 900 miles
GM estimate for two-wheel-drive trucks running the 34-gallon tank at 27 mpg highway.
Two days before the engine briefings, GM revealed a new cabin interface for its trucks. The rollout starts with the 2027 Silverado and Sierra and later extends to other models; GM calls it one scalable base that works across electric, gasoline and diesel vehicles. Screens and home-screen layout, driver-assistance controls, Apple CarPlay and Android Auto, cameras with trailering views, and over-the-air updates were all part of that September 15 announcement. None of it covers today's engine, tank or range figures.
GM unveils a new truck user interface that debuts on the 2027 Silverado and Sierra.
GM details two new V8 engines and the four-engine lineup for the 2027 light-duty trucks.
The redesigned half-ton pickups arrive later in 2026 with the new V8 options.
Why this matters
GM is betting that full-size truck buyers still want V8 and diesel choices even as rivals move toward hybrid powertrains. The four-engine lineup shapes what shoppers can order in the 2027 Silverado and Sierra, which matters to dealers and to the suppliers tied to GM's light-duty truck program. Pricing and full specifications have not been released.
Terms in This Story
- Small Block
- A long-running family of V8 engine designs from General Motors; the sixth generation is the basis of the new truck engines.
- DEF
- Diesel exhaust fluid, a urea-based liquid injected into the exhaust of modern diesel vehicles to cut emissions; the level indicator shows how much remains.
- NOx sensor
- A sensor that measures nitrogen oxides in exhaust gases, used by emissions-control systems.
- 10-speed automatic
- A transmission with ten forward gear ratios, which can spread engine power across a wider range of speeds.
A brief summary; details can be imperfect — always verify against the original source.