General Motors this week debuted two new V8 engines to power its next-generation 2027 Chevrolet Silverado 1500 and GMC Sierra 1500. GM’s sixth-generation small-block engine choices, unveiled Wednesday at Flint Engine Operations, offer customers increased capability and performance.

“GM's powertrain strategy is not about offering more engines simply to offer more engines. It's about recognizing that truck customers use their vehicles differently and giving each customer a powertrain that fits the way they work, tow, haul, commute, travel, and play. That strategy comes through in the proof points: usable torque, fuel economy under heavy use, confident trailing, durability, and emissions performance,” said Mark Dickens, GM’s executive chief engineer for full-sized trucks and SUVs.”

“For light-duty customers, we evolved our engine choices: the enhanced 2.7-liter Turbo Max, two new all-new Gen 6V8s, and the segment-exclusive 3-liter Duramax. Each has a clear role, and all four are now paired with the 10-speed automatic transmission,” he added.

The engine options for the 2027 model year GMC and Chevrolet light-duty pickups are:

• L76 5.7L Sixth Generation V8
• L78 6.6L Sixth Generation V8
• Enhanced TurboMax
• Duramax 3.0L Turbo Diesel

Small Block Returns Home to Flint

The new small block engines are manufactured in GM’s Flint Engine Operations. Mark Reuss, GM president, explained the significance Wednesday morning at the facility.

“So, there's really no better place to talk about the past, the present, and the future of GM trucks than right here in Flint, where this company was born exactly 118 years ago, Sept. 16, 1908. Flint is the home of what now is the sixth generation of our legendary small block V8, often called America's engine. The small block recently celebrated its seventh anniversary,” Reuss said.

“Actually, it's pretty awesome because it was created by a team of GM engineers, Ed Cole and Zora Arkus-Duntov, and debuted in the '55 Chevrolet, Corvette, and Bel Air. But if you really know your history, it sort of started a little bit with the 390 and Cadillac in '49, where it really it gave birth to a big technological advancement off of flatheads and everything else,” Reuss further explained.

Reuss talked about what he called the “big picture” as he detailed that GM is building a propulsion portfolio for both current and future customers while growing its truck and SUV business with advanced gasoline and diesel powertrains, plus investing in and developing new EV platforms, batteries, charging systems and software.

“Different customers need different combinations of capability, range, affordability, towing confidence, and convenience. Our aim is to meet them where they are, and be ready for where they're going next before they actually even know it and get there,” Reuss said.  “Trucks and SUVs provide the scale, the customer relationships, and cash flow to support the investment and the technologies I just mentioned. And GM has the technical breadth, depth, and scale that few companies, if any, can match when it comes to developing internal combustion and electric propulsion, and our agility and flexibility in manufacturing allow us to adjust the production schedules to meet the market wherever it is and wherever our customers are.”

GM’s New Sixth-Gen Small Block Gas Engines

The new L76 5.7L and L78 6.6L V8 engines bring GM’s next-generation small-block architecture to its light-duty truck lineup.

As with the LS6, which brought the 409-cubic-inch displacement back to the small block engine family for the 2027 Corvette Stingray, Grand Sport, and Grand Sport X, the L76 and L78 herald GM’s 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 V8s to continue to meet regulations and exceed customer expectations.

More Displacement, More Power

“As we introduce the new powertrain choices for the next-generation Silverado and Sierra, the message is straightforward: more choice, more capability, and more powertrain leadership with the right engine for every truck customer. There's no singular Silverado customer or Sierra customer. They all want a truck,” Reuss said. “They can do whatever they need to do, and we deliver the refinement, technology, and comfort they expect every day, all the time.”

In addition to the diesel powertrain offerings for light-duty pickups, he said the two new Gen 6 small block V8s in 5.7-liter and 6.6-liter configurations are an important part of that plan.

“Both engines were shaped around real truck use: towing, hauling, muting, off-road driving, and long-distance travel. They are strong under load, controlled off-road, and refined every day. These engines were designed by truck people for trucking,” Reuss explained. “This roster of engines is what powertrain leadership looks like. It's not one engine for everybody. It's the freedom to choose the engine that fits your work lifestyle and priorities, and it's the knowledge and confidence that whatever engine you choose has been thoughtfully designed, thoroughly validated, exhaustively tested, and built with quality right here.”

The layout of the new engines begins with an architectural element shared with more than 100 million small block engines dating back to 1955: cylinder bore centers spaced at 4.40-inch intervals.

To generate more horsepower and torque from the new light-duty truck V8s, 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 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 V8 delivers 402 horsepower and 428 lb.-ft. of torque. GM said that 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.

GM said the 6.6L V8 is the most powerful naturally aspirated V8 engine in its class, with 481 horsepower and 501 lb.-ft. of torque.

“These new V8 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 V8.”

New Features in GM’s Sixth-Gen Gas Engines

Additional, significant 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.

Powertrain Portfolio Built Around Customer Choice

The new V8 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 Guide

Payload and maximum towing varies by vehicle configuration, trim and available packages.

GM's Diesel Powertrain Options

TurboMax

An enhanced TurboMax with best-in-class standard torque adds 40 horsepower and 25 lb.-ft. of torque, improving performance, drivability, and noise and vibration refinements.

Updates include a new turbocharger, upgraded fuel injection system, improved active thermal management, and redesigned pistons. Now paired with a 10-speed automatic transmission, the engine is designed to deliver smoother shifts, stronger power delivery, and improved towing performance.

Duramax 3.0L Turbo Diesel

The segment-exclusive Duramax 3.0L Turbo Diesel returns with 305 horsepower and 495 lb.-ft. of torque, continuing to offer smooth, quiet operation and strong low-end torque for towing, long-distance driving and everyday use. Updates include revised DEF level indicators and additional target improvements, including piston, turbo vane, next-generation NOx sensor, sealing, and fuel injector corrosion-protection updates. Those improvements are intended to support performance, reliability, and customer confidence.

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 V8s, and when paired with the Duramax 3.0L Turbo-Diesel, offers a highway driving range of over 900 miles.

North American Manufacturing Investment

The next-generation powertrain portfolio reflects the talented workforce behind GM’s full-size truck business. Production of the new 5.7L and 6.6L V8 engines will be performed by the talented teams at GM’s Flint Engine Operations, Tonawanda Propulsion, and St. Catharines Propulsion plants.

GM has previously announced significant North American manufacturing investments to support next-generation truck and V8 production, as part of a $9-billion investment across U.S. manufacturing, including $888 million at Tonawanda Propulsion in New York for sixth-generation V8 engines for full-size trucks and SUVs.

GM Investment in Canada

In Canada, GM is investing C$691 million at St. Catharines Propulsion to support production of its sixth-generation V8 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.

Availability of the Sixth-Gen V8 Engines

The new 5.7L and 6.6L V8 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.