New GM Truck Powertrain Options for 2027: Silverado Engines Explained

The new GM truck powertrain options for 2027 represent one of the biggest mechanical changes to the Chevrolet Silverado 1500 in years. The redesigned half-ton keeps four distinct engine choices, but two of them are completely new sixth-generation Small Block V8s, while the TurboMax four-cylinder receives a meaningful upgrade. The 3.0-liter Duramax diesel remains the torque-rich long-distance option.

Car and Driver’s 2027 Chevrolet Silverado 1500 preview originally described the new 5.7- and 6.6-liter V8s before Chevrolet had published final output figures. GM has since released full specifications, so the current picture is clearer: the lineup now spans from a 350-hp TurboMax to a 481-hp naturally aspirated 6.6-liter V8, and every engine is paired with a 10-speed automatic transmission.

What Are the Four 2027 GM Truck Powertrain Options?

Chevrolet’s official 2027 Silverado information lists a maximum of 481 hp, 501 lb-ft of torque, and up to 13,700 pounds of available trailering. The Silverado and next-generation GMC Sierra share the same basic four-engine strategy.

Enhanced 2.7L TurboMax: More Power and a New Transmission

The TurboMax remains the smallest engine in the lineup, but it receives one of the largest year-over-year improvements. GM rates the 2027 version at 350 hp and 455 lb-ft of torque. That is an increase of 40 hp and 25 lb-ft compared with the 2026 Silverado’s 310-hp, 430-lb-ft TurboMax.

GM says the upgrade includes a new turbocharger, improved fuel injection, revised pistons, and updated thermal management. The bigger practical change is behind the engine: the TurboMax now uses the same 10-speed automatic transmission as the other Silverado powertrains. The outgoing TurboMax used an eight-speed.

This makes the base engine more competitive for drivers who want useful low-rpm torque without paying for a V8 or diesel. It should also give Chevrolet more flexibility in keeping the engine near its strongest operating range when towing or climbing grades.

Who Should Consider the TurboMax?

The TurboMax is aimed at buyers whose trucks spend most of their time commuting, carrying moderate loads, or handling normal work duties. Its 455 lb-ft torque figure is substantial for a standard engine, but shoppers who tow near the upper end of the Silverado’s capability may still prefer the diesel or a V8.

3.0L Duramax Diesel: The Familiar Torque and Range Choice

GM did not replace the 3.0-liter Duramax inline-six for 2027. It continues with 305 hp and 495 lb-ft of torque, which means its advantage is not peak horsepower but strong low-speed pull and relaxed highway operation.

GM’s 2027 Sierra specification release says the Duramax can exceed 900 miles of GM-estimated highway range when paired with the available approximately 34-gallon fuel tank. Actual range will depend on configuration, load, speed, weather, and driving conditions.

For drivers who cover long interstate distances or tow regularly, the diesel’s 495 lb-ft of torque arriving at relatively low engine speed remains appealing. The tradeoffs include diesel fuel pricing, emissions-system complexity, and potentially higher maintenance costs compared with a gasoline engine.

New 5.7L V8: The Middle Ground Returns

The new 5.7-liter V8 is one of the most interesting changes because it replaces the role previously filled by the 5.3-liter EcoTec3. GM rates the Gen-6 5.7 at 402 hp and 428 lb-ft of torque. The 2026 5.3 made 355 hp and 383 lb-ft, so the new engine gains 47 hp and 45 lb-ft.

This is not simply the old engine with a larger bore or stroke. GM describes the new V8 family as a ground-up sixth-generation Small Block design. Both new V8s use higher compression ratios, larger throttle bodies, tuned intake manifolds, and a dual-fuel injection system that combines direct injection with port injection.

The 5.7 keeps the traditional overhead-valve layout with two valves per cylinder and variable valve timing. That compact architecture has been central to GM truck V8s for decades.

Why the 5.7L V8 May Be the Sweet Spot

With 402 hp, the 5.7 is much closer to the outgoing 6.2-liter V8’s power level than the old 5.3 was. It offers buyers a naturally aspirated V8 without stepping all the way to the largest engine. GM also lists up to 13,500 pounds of available trailering with the 5.7 in the related Sierra when properly equipped.

New 6.6L V8: GM’s Most Powerful Half-Ton Naturally Aspirated V8

The headline engine is the new 6.6-liter Gen-6 Small Block. It produces 481 hp and 501 lb-ft of torque, making it substantially stronger than the previous 6.2-liter EcoTec3, which was rated at 420 hp and 460 lb-ft.

GM calls the 6.6 the most powerful naturally aspirated V8 in its class and the company’s most powerful half-ton V8 to date. The engine uses an aluminum block with cast-iron liners, variable valve timing, and the same direct-plus-port fuel-injection strategy as the 5.7.

For buyers who want immediate gasoline-engine response without turbocharging, the 6.6 becomes the clear flagship. It also helps move the Silverado’s maximum available tow rating to 13,700 pounds when the truck is properly configured.

How Do the New Engines Compare With the 2026 Silverado?

The biggest gains come from the gasoline engines. The diesel carries over its core output, while the TurboMax moves closer to V8 horsepower. The 5.7 and 6.6 make the old 5.3 and 6.2 look modest by comparison.

Why Does the Standard 10-Speed Automatic Matter?

For 2027, every Silverado 1500 engine uses a 10-speed automatic. That simplifies the powertrain lineup and gives the TurboMax two additional forward ratios compared with the outgoing eight-speed.

More ratios do not automatically make a transmission better, but they allow smaller steps between gears. In a truck, that can help the engine stay closer to its useful torque band under changing loads, grades, and towing conditions. GM pairs the TurboMax with a 3.42 axle ratio, while the 5.7, 6.6, and Duramax use a 3.23 ratio in the published Sierra specifications.

Which Engine Is Best for Towing?

The answer depends on trailer weight, driving distance, terrain, payload, and how often the truck tows. Maximum tow ratings also depend on cab, bed, drivetrain, axle, and equipment, not just engine choice.

• TurboMax: strong standard torque and suitable for many moderate towing jobs.
• Duramax 3.0L: excellent low-rpm torque and highway range for frequent long-distance towing.
• 7L V8: a strong gasoline middle ground with up to 13,500 pounds of available trailering in related Sierra specifications.
• 6L V8: the highest gasoline output and part of Silverado configurations that reach up to 13,700 pounds of available towing.

Are the New V8s Hybrid Engines?

No. The 5.7- and 6.6-liter engines are conventional naturally aspirated gasoline V8s rather than hybrid powertrains. GM has focused this generation on improving the Small Block itself instead of replacing it with a turbocharged six-cylinder or hybrid-only setup.

That decision gives Silverado and Sierra buyers a wider spread of traditional powertrain choices at a time when several competitors are leaning more heavily on turbocharged or electrified engines.

What About GM Heavy-Duty Truck Engines?

The Silverado 1500 powertrains should not be confused with GM’s 2027 heavy-duty lineup. Silverado HD and Sierra HD introduce a separate 8.3-liter Duramax turbo-diesel V8 rated at 555 hp and 1,230 lb-ft of torque. That engine is designed for heavy-duty towing and hauling and is not offered in the half-ton Silverado 1500.

Keeping those lineups separate is important because the 6.6-liter V8 discussed here is the new gasoline half-ton engine, not the existing or new heavy-duty diesel.

Frequently Asked Questions About the New GM Truck Powertrains

What Is the Most Powerful 2027 Silverado 1500 Engine?

The new 6.6-liter Gen-6 Small Block V8 is the most powerful, with 481 hp and 501 lb-ft of torque.

Did GM Discontinue the 5.3L and 6.2L V8s?

For the next-generation 2027 Silverado 1500 lineup, the new 5.7- and 6.6-liter V8s replace the previous 5.3- and 6.2-liter choices.

Does the 2027 Silverado Still Offer a Diesel?

Yes. The 3.0-liter Duramax turbo-diesel inline-six continues with 305 hp and 495 lb-ft of torque.

Does Every 2027 Silverado Get a 10-Speed Automatic?

Yes. Chevrolet lists the 10-speed automatic as standard with all four engines, including the upgraded TurboMax.

What Is the Bottom Line?

The new GM truck powertrain options give the 2027 Silverado 1500 a much stronger gasoline lineup without abandoning diesel or the entry-level turbo four-cylinder. The TurboMax rises to 350 hp, the 5.7-liter V8 brings 402 hp, and the new 6.6-liter V8 tops the range at 481 hp. The Duramax remains at 305 hp and 495 lb-ft for buyers who value diesel torque and long-range efficiency.

For shoppers, the biggest change is choice without a major gap in capability. The TurboMax is far stronger than before, the 5.7 becomes a compelling V8 middle ground, the 6.6 delivers flagship naturally aspirated power, and the Duramax remains the specialized highway and towing option. Final engine availability by trim and exact tow ratings still depend on configuration, so buyers should verify the specific truck before ordering.