General Motors has announced two new V-8 engines for its next-generation light-duty pickup portfolio that includes the 2027 Chevrolet Silverado 1500 and GMC Sierra 1500, providing full-size pickup truck customers with increased capability and performance from GM’s sixth-generation small-block architecture, according to a press release.
The new L76 5.7L and L78 6.6L V-8 engines join the LS6 6.7L V-8 developed for the 2027 Corvette Stingray, Grand Sport and Grand Sport X. As with the LS6, which brought the 409-cubic-inch displacement back to the small-block engine family, the L76 and L78 herald the return of the 350- and 400-cubic-inch displacements, respectively.
The new engines were developed with advanced modeling and simulation toolsets, plus proven hardware efficiency and durability testing, enabling small-block V-8s to continue to meet regulations and exceed customer expectations, the company said.
How GM Increased Displacement & Horsepower
The layout of the new engines begins with cylinder bore centers spaced at 4.40-inch intervals, an architectural element of small-block engines dating back to 1955.
To generate more horsepower and torque from the new light-duty truck V-8s, GM engineers applied several key enablers:
- Increased displacement from 5.3L and 6.2L to 5.7L (350 cubic inches) and 6.6L (400 cubic inches), respectively, by increasing piston stroke by 6 mm
- Higher compression ratio for more efficient combustion
- More airflow via larger throttle diameters
- New intake manifolds with tuned runners to manage the additional airflow
The 5.7L V-8 delivers 402 horsepower and 428 pound-feet of torque. According to GM, no other truck in the segment tows more than its light-duty trucks, and the Silverado 1500 achieves a best-in-class maximum available tow rating of 13,700 pounds when properly equipped.
The 6.6L V-8 is the most powerful naturally aspirated V-8 engine in its class, with 481 horsepower and 501 pound-feet of torque, company officials added.
“These new V-8 engines advance GM’s legendary small-block architecture with greater capability, more advanced technology and the strength of GM’s manufacturing footprint behind them,” said Tom Bishop, chief engineer for small-block engines. “They’re engineered to provide truck customers the confidence and performance they expect from a GM V-8.”
Additional sixth-generation features include:
- A dual-fuel system that combines direct injection and port fuel injection for expanded operation in optimal power, efficiency and emissions windows
- New lubrication system featuring a continuously variable oil pump, on-engine oil cooler and reworked oil feed locations for additional oil pressure consistency
Both engines are developed for the everyday demands of full-size trucks, from towing and hauling to commuting and off-road driving. By the time the next-generation trucks arrive at dealerships later this year, GM development teams expect to complete more than 1.5 million miles (2.4 million km) of real-world, on-road validation, the release noted.
Four-Engine Lineup for Next-Gen Silverado & Sierra
The new V-8 engines join the Enhanced TurboMax and available Duramax 3.0L Turbo-Diesel offerings in a four-engine lineup for the next-generation Silverado 1500 and Sierra 1500.
Next-Generation Light-Duty Powertrain Quick Reference
| Engine | Horsepower | Torque | Maximum towing* | Maximum Payload* |
| Enhanced TurboMax | 350 | 455 pound-feet | 9,400 pounds | 2,340 pounds (Silverado)/2,310 pounds (Sierra) |
| Duramax 3.0L Turbo-Diesel | 305 | 495 pound-feet | 12,000 pounds (Silverado)/12,100 pounds (Sierra) | 1,870 pounds (Silverado)/1,850 pounds (Sierra) |
| L76 5.7L Sixth Generation V-8 | 402 | 428 pound-feet | 13,700 pounds (Silverado)/13,500 pounds (Sierra) | 2,170 pounds (Silverado)/2,140 pounds (Sierra) |
| L78 6.6L Sixth Generation V-8 | 481 | 501 pound-feet | 9,700 pounds (Silverado)/9,400 pounds (Sierra) | 1,510 pounds (Silverado)/1,450 pounds (Sierra) |
| *Payload and Maximum towing vary by vehicle configuration, trim and available packages. | ||||
All engines for GM’s 2027 light-duty truck lineup are paired with a 10-speed automatic transmission. A new 34-gallon (129-liter) fuel tank is available for the 5.7L and 6.6L V-8s, and when paired with the Duramax 3.0L Turbo-Diesel, offers a highway driving range of over 900 miles.
Investing in North American Manufacturing
Production of the new 5.7L and 6.6L V-8 engines will be performed at GM’s Flint Engine Operations, Tonawanda Propulsion, and St. Catharines Propulsion plants.
GM has previously announced North American manufacturing investments to support next-generation truck and V-8 production, as part of a $9 billion investment across U.S. manufacturing, including $888 million at Tonawanda Propulsion in New York for sixth-generation V-8 engines for full-size trucks and SUVs.
In Canada, GM is investing C$691 million (around $493 million USD) at St. Catharines Propulsion to support production of its sixth-generation V-8 engines, which power full-size trucks and SUVs. GM has also announced additional investments in facilities supporting related truck manufacturing and 10-speed transmission capacity.
The new 5.7L and 6.6L V-8 engines will be available with the launch of the next-generation Chevrolet Silverado 1500 and GMC Sierra 1500 later this year. Additional vehicle information, including MSRP, will be shared in future updates, the company said.