Rivard Buick GMC · Tampa, FL
2027 GMC Sierra 1500 Engines
The 2027 Sierra 1500 launches with four confirmed engines, headlined by two all-new sixth-generation Small Block V8s: a 5.7L and a 6.6L, the most powerful naturally aspirated V8 in its class. The enhanced TurboMax 2.7L and the class-exclusive Duramax 3.0L Turbo-Diesel round out the lineup, and every engine pairs with a 10-speed automatic. Here is everything GMC has confirmed, what remains unannounced, and how the new lineup compares with the engines it replaces.
The Lineup
What Engines Will the 2027 GMC Sierra 1500 Offer?
Last updated September 17, 2026 by Rivard Buick GMC
GMC confirmed four engines for the 2027 Sierra 1500 at the June 25, 2026 reveal: an all-new sixth-generation 6.6L V8 (standard on Denali Ultimate and the most powerful naturally aspirated V8 in its class), an all-new sixth-generation 5.7L V8, the class-exclusive Duramax 3.0L Turbo-Diesel inline-six, and an enhanced TurboMax 2.7L turbocharged four-cylinder with best-in-class standard torque. Every engine is paired with a 10-speed automatic transmission.
Output, towing, and payload figures for all four engines are now confirmed. What GMC has not yet released: fuel economy and which engines are available on which trims beyond the Denali Ultimate's standard 6.6L. This page separates what is confirmed from what remains open, and we update it as GM releases the rest.
The Headliner
The All-New 6.6L V8: Most Powerful Naturally Aspirated V8 in Its Class
The sixth-generation 6.6L V8 is the flagship engine of the 2027 Sierra 1500 and comes standard on the Denali Ultimate. GMC has confirmed the output: 481 horsepower and 501 lb-ft of torque, backing up the class claim by clearing GM's own outgoing 420-horsepower 6.2L by a wide margin. Maximum towing and payload are confirmed too; see the full comparison against the outgoing 6.2L below.
All-New · Gas V8
6.6L V8
Sixth-generation Small Block architecture with advances in combustion, cooling, and control systems, plus a new fuel injection system.
- ReplacesThe outgoing 6.2L V8
- GenerationAll-new sixth-generation Small Block V8
- Class PositionMost powerful naturally aspirated V8 in its class (confirmed by GMC)
- OutputConfirmed at 481 hp and 501 lb-ft of torque
- Transmission10-speed automatic
- AvailabilityStandard on Denali Ultimate; availability on other trims not announced
- EngineeringNew fuel injection system tuned across daily driving, towing, and off-road use
The Volume V8
The All-New 5.7L V8
The second new engine is a 5.7L sixth-generation Small Block V8, positioned as the strong, capable mainstream V8 of the lineup, the successor role held by the 5.3L in the outgoing generation. It shares the sixth-generation architecture and new fuel injection system with the 6.6L. GMC has confirmed the output: 402 horsepower and 428 lb-ft of torque, well above the outgoing 5.3L's 355 horsepower and 383 lb-ft, with a meaningful jump in maximum towing as well.
All-New · Gas V8
5.7L V8
The mainstream V8 of the fifth-generation Sierra, built on the same all-new architecture as the 6.6L.
- ReplacesThe outgoing 5.3L V8
- GenerationAll-new sixth-generation Small Block V8
- RoleSuccessor to the volume V8 position held by the outgoing 5.3L
- OutputConfirmed at 402 hp and 428 lb-ft of torque
- Transmission10-speed automatic
- AvailabilityTrim availability not announced
- EngineeringShared combustion, cooling, and control advances with the 6.6L
Class Exclusive
Duramax 3.0L Turbo-Diesel: Still the Only Diesel in the Class
The Duramax 3.0L Turbo-Diesel inline-six continues into the 2027 Sierra 1500, and GMC's claim holds for the new generation: no other competitor in the class offers an available diesel. Output is confirmed unchanged at 305 horsepower and 495 lb-ft of torque, the same figures that built its loyal following with owners who tow. Maximum towing is confirmed lower than the outgoing generation; see the full comparison below.
Class-Exclusive Diesel
Duramax 3.0L Turbo-Diesel
The torque-rich, efficiency-focused choice, and the only diesel offered by any truck in this class.
- ConfigurationTurbocharged 3.0L inline-six diesel
- Class PositionClass-exclusive: no competitor offers an available diesel (confirmed by GMC)
- 2027 OutputConfirmed unchanged at 305 hp and 495 lb-ft of torque
- Transmission10-speed automatic
- Best ForTowing range and highway efficiency
- AvailabilityTrim availability not announced
The Standard Bearer
Enhanced TurboMax 2.7L: Best-in-Class Standard Torque
The TurboMax 2.7L turbocharged four-cylinder returns in enhanced form and carries a confirmed GMC claim: best-in-class standard torque. For 2027 it continues with meaningful hardware and calibration changes. GMC has confirmed the enhancement: output rises to 350 horsepower and 455 lb-ft of torque, up from 310 hp and 430 lb-ft in the outgoing generation, with maximum payload up as well and maximum towing unchanged.
Enhanced Turbo Four
TurboMax 2.7L
The proven turbocharged four-cylinder, enhanced for 2027 with best-in-class standard torque.
- ConfigurationTurbocharged 2.7L inline four-cylinder
- Class PositionBest-in-class standard torque (confirmed by GMC)
- 2027 OutputConfirmed at 350 hp and 455 lb-ft of torque, up from 310 hp / 430 lb-ft
- Transmission10-speed automatic (up from 8-speed in the outgoing truck)
- RoleExpected standard engine on volume trims; official trim mapping not announced
- Best ForDaily driving with serious torque and lower cost of entry
Signal vs. Noise
2027 Sierra 1500 Engine Specs: Confirmed, Estimated, Not Announced
The table below separates GMC's official statements from independent press estimates and open questions. Anything marked Estimate comes from automotive press analysis, not from GM, and can change when official figures drop.
| Topic | Status | Details |
|---|---|---|
| Engine Lineup | Confirmed | Four engines: all-new 6.6L V8, all-new 5.7L V8, Duramax 3.0L Turbo-Diesel, enhanced TurboMax 2.7L. |
| Transmission | Confirmed | 10-speed automatic paired with every available engine. |
| 6.6L Class Claim | Confirmed | Most powerful naturally aspirated V8 in its class, per GMC. Standard on Denali Ultimate. |
| 6.6L Output | Confirmed | 481 hp and 501 lb-ft of torque. Clears GM's own outgoing 420 hp 6.2L by 61 horsepower, backing up the most-powerful-in-class claim. |
| 5.7L Output | Confirmed | 402 hp and 428 lb-ft of torque, up from the outgoing 5.3L's 355 hp and 383 lb-ft. |
| TurboMax Claim | Confirmed | Best-in-class standard torque, per GMC. Output confirmed at 350 hp and 455 lb-ft, up from 310 hp / 430 lb-ft. |
| Duramax Diesel | Confirmed | Class-exclusive 3.0L Turbo-Diesel continues. Output confirmed unchanged at 305 hp / 495 lb-ft. |
| V8 Engineering | Confirmed | Sixth-generation Small Block architecture with advances in combustion, cooling, and control systems, and a new fuel injection system tuned for daily driving through towing and off-road use. |
| Production Start | Reported | Industry reporting points to start of regular production in mid-Q4 2026, with October 2026 the most commonly cited window. GM has not issued a formal production date and the timing remains tentative. |
| Towing & Payload | Confirmed | Maximum towing ranges from 9,400 to 13,500 lbs and maximum payload from 1,450 to 2,310 lbs, depending on engine. Full 2026-vs-2027 comparison below. Available Super Cruise with trailering is confirmed across more of the lineup than any previous Sierra. |
| Fuel Economy | Not Announced | EPA figures will be published closer to launch. |
| Engine-by-Trim Availability | Not Announced | Only confirmed pairing: 6.6L V8 standard on Denali Ultimate. Full trim-by-engine mapping arrives with the order guide. |
| Hybrid or PHEV | Not Announced | GMC has not announced any hybrid powertrain for the 2027 Sierra 1500. Electric truck buyers are served by the separate Sierra EV. |
Sources include the official GMC press release on the 2027 Sierra 1500 and analysis from GM Authority, Car and Driver, and MotorTrend. Rivard Buick GMC updates this page as official specifications are released.
Generation Change
What Happened to the 5.3L and 6.2L V8s?
The familiar 5.3L and 6.2L V8s do not carry into the fifth-generation Sierra. Both are replaced by the new sixth-generation Small Block family: the 5.7L steps into the volume V8 role held by the 5.3L, and the 6.6L takes over the top spot from the 6.2L. If you specifically want a 5.3L or 6.2L Sierra, the 2026 model year is the last chance to buy one new, and we have them in stock in Tampa today.
2026 Sierra Engines
Final Year, In Stock- 2.7L TurboMax I-4310 hp / 430 lb-ft, 8-speed automatic
- 5.3L EcoTec3 V8355 hp / 383 lb-ft, the long-running volume V8
- 6.2L EcoTec3 V8420 hp / 460 lb-ft, the outgoing performance flagship
- 3.0L Duramax Diesel305 hp / 495 lb-ft, efficiency and towing champion
- StatusPublished specs, published pricing, available now at Rivard Buick GMC Tampa
2027 Sierra Engines
Late 2026- Enhanced 2.7L TurboMax I-4350 hp / 455 lb-ft, best-in-class standard torque, now with a 10-speed automatic
- All-New 5.7L V8402 hp / 428 lb-ft, sixth-generation Small Block, replaces the 5.3L role
- All-New 6.6L V8481 hp / 501 lb-ft, most powerful NA V8 in class, replaces the 6.2L role
- 3.0L Duramax Diesel305 hp / 495 lb-ft, continues as the only diesel in the class
- StatusOutput, towing, and payload confirmed; pricing to be announced before launch
What Is the Sixth-Generation Small Block?
The Small Block is GM's V8 family dating back to 1955, and the engines in today's trucks are fifth-generation designs introduced in 2014. The 2027 Sierra debuts the sixth generation: new displacements (5.7L and 6.6L), a new fuel injection system, and updated combustion, cooling, and control systems engineered for refinement and durability across daily driving, towing, and off-road use. It is the first new Small Block generation in over a decade, which is a large part of why this redesign matters.
Confirmed Specs
2026 vs 2027 Sierra 1500 Engine Comparison
GMC has confirmed horsepower, torque, maximum towing, and maximum payload for all four 2027 engines. The table below pairs each new engine with the outgoing engine it replaces so you can see exactly what changed.
| Engine | Horsepower | Torque | Max Towing (lbs)1 | Towing vs 2026 | Max Payload (lbs)1 | Payload vs 2026 |
|---|---|---|---|---|---|---|
| Enhanced TurboMax 2.7L | 350 hp | 455 lb-ft | 9,400 | No change | 2,310 | +80 |
| Duramax 3.0L Turbo-Diesel | 305 hp | 495 lb-ft | 12,100 | -1,200 | 1,850 | -30 |
| All-New 5.7L V8 | 402 hp | 428 lb-ft | 13,500 | +2,300 | 2,140 | -10 |
| All-New 6.6L V8 | 481 hp | 501 lb-ft | 9,400 | -3,700 | 1,450 | -420 |
1 Maximum ratings when properly equipped; capability varies by cab, bed, drivetrain and equipment.
Figures from the official GMC press release on the 2027 Sierra 1500. Rivard Buick GMC updated this comparison September 17, 2026.
Capability
Built to Tow, With Super Cruise That Tows With You
Maximum towing and payload are confirmed for every 2027 Sierra 1500 engine (see the comparison above), and available Super Cruise with trailering expands across more of the lineup than any previous Sierra, supporting hands-free driving on more than 600,000 miles of compatible roads, with the Denali Ultimate including a standard three-year subscription. For Tampa Bay owners pulling boats to the ramp or equipment across Hillsborough County, the pairing of new V8 power and hands-free trailering is the headline capability story of this generation. Read more about how it works on our Super Cruise page.
Now Taking Orders
Order Your 2027 Sierra 1500
Ordering is open at Rivard Buick GMC, and no deposit is required to place an order. Output, towing, and payload are now confirmed for all four engines, so tell us in the comments which engine and trim you want and our team will spec your build and place the order. You get first access to allocation at Tampa Bay's highest-volume GMC dealer.
Want a V8 truck sooner? The 2026 Sierra 1500 with the proven 5.3L, 6.2L, TurboMax, and Duramax engines is on the ground today with published pricing.
Order Your 2027 Sierra
Start Your 2027 Sierra Order
FAQ
2027 Sierra 1500 Engines: Frequently Asked Questions
What engines will the 2027 GMC Sierra 1500 have?
Four confirmed engines: an all-new sixth-generation 6.6L V8 (standard on Denali Ultimate), an all-new sixth-generation 5.7L V8, the class-exclusive Duramax 3.0L Turbo-Diesel inline-six, and an enhanced TurboMax 2.7L turbocharged four-cylinder with best-in-class standard torque. All four pair with a 10-speed automatic transmission.
How much horsepower will the 2027 Sierra 1500 have?
GMC has confirmed official output for all four engines: 481 hp / 501 lb-ft for the 6.6L V8, 402 hp / 428 lb-ft for the 5.7L V8, 350 hp / 455 lb-ft for the enhanced TurboMax 2.7L, and 305 hp / 495 lb-ft for the Duramax 3.0L Turbo-Diesel. See the full 2026-vs-2027 comparison, including towing and payload, above.
Is the 2027 Sierra 1500 replacing the 5.3L and 6.2L V8s?
Yes. The fifth-generation 5.3L and 6.2L EcoTec3 V8s do not continue into the 2027 Sierra 1500. They are replaced by the all-new sixth-generation 5.7L and 6.6L Small Block V8s. The 2026 Sierra 1500 is the final model year for the 5.3L and 6.2L.
Does the 2027 Sierra 1500 still offer a diesel engine?
Yes. The Duramax 3.0L Turbo-Diesel inline-six continues in the 2027 Sierra 1500, and it remains class-exclusive: no other truck in the class offers an available diesel. Output is confirmed unchanged at 305 horsepower and 495 lb-ft of torque; maximum towing is confirmed lower than the outgoing generation. See the full comparison above.
What transmission does the 2027 Sierra 1500 use?
A 10-speed automatic is paired with every available engine, including the TurboMax 2.7L, which used an 8-speed in the outgoing generation.
Will there be a hybrid 2027 GMC Sierra?
GMC has not announced a hybrid or plug-in hybrid powertrain for the 2027 Sierra 1500. The confirmed lineup is two gas V8s, the TurboMax turbo four, and the Duramax diesel. Buyers who want an electric GMC truck are served by the separate Sierra EV.
Which engine comes standard on the Denali Ultimate?
The all-new 6.6L V8 is standard on the 2027 Sierra 1500 Denali Ultimate. It is the only confirmed engine-to-trim pairing so far; the full engine availability map for Pro, Elevation, AT4, Denali, and AT4X arrives with the official order guide.
When does 2027 Sierra 1500 production start?
GM has not published a formal production date. Industry reporting points to start of regular production in mid-Q4 2026, with October 2026 the most commonly cited window, and that timing is described as tentative. GMC has confirmed the first 2027 Sierra 1500 trucks are expected at dealerships before the end of the 2026 calendar year.
Can I order a 2027 Sierra 1500 now?
Yes. Rivard Buick GMC Tampa is accepting 2027 Sierra 1500 orders now, with no deposit required. GMC has not released pricing, and first trucks are expected at dealerships before the end of the 2026 calendar year. Start your order here.
Explore
More on the 2027 Sierra and Today's Lineup
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2027 Sierra Interior & Tech
2027 Sierra Colors & Paint
2026 Sierra 1500 Overview
Shop Sierra 1500 Inventory
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