GM - General Motors Company

09/24/2026 | Press release | Distributed by Public on 09/24/2026 08:01

GM raises the bar for Heavy-Duty power, capability and control headlined by all-new Duramax 8.3L Turbo-Diesel V8 engine

Close up shot of the badging for the new 8.3L Duramax Turbo-Diesel V8 on the hood of a 2027 Chevrolet Silverado HD.
  • GM introduces an available all-new Duramax 8.3L Turbo-Diesel V8 engine with best-in-class horsepower and torque for HD truck lineup1.
  • Segment-first rack-and-pinion Electric Power Steering and electronic brake-boost system bring greater control, precision and confidence to HD trucks.
  • Improved drive modes and integrated trailering technology help handle demanding towing, hauling and off-road conditions.

DETROIT - General Motors today unveiled updates for its new 2027 heavy-duty truck lineup which will launch this year on the Chevrolet Silverado HD and GMC Sierra HD, engineered as a holistically integrated system to deliver more power, control and confidence for customers who demand maximum capability from their trucks every day.

Over 60 percent of heavy-duty customers opt for a diesel engine when purchasing their truck. GM's brands already account for the majority of diesel share in the segment. These substantive updates will further strengthen GM's position in the marketplace.

Central to the updates are GM's first all-new, in-house-designed heavy-duty diesel engine option, segment-first rack-and pinion Electric Power Steering and a new electronic brake-boost architecture - technologies developed to deliver a more refined, commanding HD experience when towing, hauling or driving off-road.

Highlights

  • Available all-new Duramax 8.3L Turbo-Diesel V8 engine with best-in-class diesel horsepower and torque at 555 hp / 1,230 lb.-ft.
  • Maximum available trailering capability of up to 20,000 pounds conventional and up to 38,000 pounds gooseneck on properly equipped models.
  • Enhanced 6.6L gas V8 now delivers 412 horsepower and best-in-class standard torque among all 2027 model-year HD gas engines at 472 lb.-ft.
  • Segment-first rack-and-pinion Electric Power Steering for HD trucks, tuned for more precise steering feel, reduced kickback and quieter operation on- and off-road.
  • Segment first electronic brake-boost system, with larger brakes and four-piston front calipers for confident, more consistent stopping.
  • Enhanced drive-mode strategy, including updated Tow/Haul and Off-Road calibrations and a new available Terrain Mode with one-pedal off-road control - a first for GM HD trucks.

"For 2027, we took GM's proven HD validation playbook and turned up the capability - integrating new powertrain, braking, steering and chassis technologies for serious customers who push their trucks hard every day," said Mark Dickens, Executive Chief Engineer for GM Full Size Trucks and SUVs. "HD customers don't hold back - and neither did we."

All-New GM Heavy-Duty Diesel & Enhanced Gas Engine

The all-new available diesel is GM's first clean-sheet HD V8 designed, developed and manufactured in-house for heavy-duty pickup applications.

Key benefits include:

  • All-new, GM-developed HD diesel architecture, designed specifically around heavy-duty pickup customers, with a compacted graphite iron cylinder block and fully forged crankshaft, connecting rods and steel pistons forming the foundation for strength and durability.
  • More confident power and towing, with best-in-class diesel horsepower and torque, supported by a broad torque curve, high-flow fuel injection and vehicle integration focused on launching heavy trailers, climbing grades and maintaining control under load.
  • Advanced cooling and turbocharging systems built for towing, including a compact dual-stage air-to-water charge cooling system, high-efficiency variable-geometry turbocharger and upgraded engine-cooling strategy to help deliver consistent performance when the truck is working hard.
  • Improved refinement and drivability, with the new engine architecture, integrated intake design, advanced combustion system and crankshaft isolation hardware helping reduce noise and vibration while supporting a more confident HD driving experience.
  • Integrated diesel system engineered as a complete package, pairing the engine with the Allison 10-speed transmission, upgraded exhaust braking capability and a new aftertreatment layout designed to support heavy-duty performance, regeneration functionality and customer confidence over long-distance towing.

"This new diesel engine is the culmination of decades of GM diesel development and integration," said Norman Peralta, Executive Chief Engineer, Global Engine and Battery Systems. "From the clean-sheet architecture and combustion system to the cooling, aftertreatment and transmission calibration, this is a powertrain built with heavy duty purpose and pride."

The new engine will be built at GM's expanded DMAX facility in Brookville, Ohio2, a 1.4-million-square-foot plant that brings machining and assembly for the engine together under one roof. GM had previously invested $920 million to grow the DMAX to handle this high-volume engine program.

The standard, enhanced 6.6L gas V8, assembled at GM's Tonawanda Engine Plant in New York2, also gains horsepower and torque1, with improved low-end pull and updated emissions hardware supported by a new Turbo-Jet intake manifold, revised lubrication system, engine-mounted oil cooler and digital oil-level display.

Both the new diesel and updated 6.6L gas V8 are paired with the Allison 10-speed 10L1000 transmission and advanced shift logic to help keep each engine in its optimal range for smoother acceleration, stronger grade performance and more confident control with heavy trailers.

A 2027 Chevrolet HD ZR2 positioned off-road. Preproduction model shown. Actual production model may vary.

Electric Power Steering: Precision You Can Feel

For 2027, GM's HD pickups move to an all-new rack-and-pinion Electric Power Steering system - a segment-first for heavy-duty trucks, replacing the previous hydraulic-assisted steering system with an all-new Electric Power Steering architecture designed specifically for heavy-duty truck demands.

The Electric Power Steering system helps to deliver:

  • Higher steering output built for serious work, with approximately 30% more power than the current HD hydraulic steering gear to support heavy front-axle loads, low-speed maneuvering, towing and demanding work-truck use.
  • More precise, consistent steering in demanding conditions, with expanded drive-mode tuning, improved on-center feel and reduced kickback to help drivers feel more in command on highways, jobsites, rough roads and trails.
  • A cleaner, quieter and lower-maintenance system, eliminating hydraulic pumps, hoses, fluid and related hardware to reduce traditional steering noise, lower system complexity and improve the ownership experience for customers who depend on their trucks every day.
  • HD-grade durability and protection, with built-in system redundancy plus corrosion- and impact-resistant hardware designed for harsh heavy-duty truck environments, including rough terrain, road debris and severe-duty use.
  • Independent functionality: electric steering allows full steering assist capability regardless of engine speed or brake assist utilization, helping to optimize vehicle maneuverability and performance for driver confidence.

Together, the new EPS system provides GM's HD trucks a modern steering foundation - one that is stronger, quieter and more precisely tuned for the way customers use their trucks. From tight low-speed maneuvers and heavy towing to rough roads and off-road terrain, the system is designed to help drivers feel more connected, more in control and more confident behind the wheel.

New HD Brake System: More Stopping Power and Brake Intelligence

Featuring a segment first electronic brake-boost system in a heavy-duty pickup, GM is introducing modern brake technology to the HD segment while still delivering the strength customers expect from the hardest working trucks.

Benefits include:

  • First-ever electronic braking for an HD pickup, designed for heavy-duty capability and control.
  • Stronger, more consistent stopping performance, with larger 14.6-inch front rotors, new four-piston fixed front calipers and upgraded rear hardware that help improve thermal capacity, brake pedal stiffness and braking confidence with big trailers.
  • More linear, predictable pedal feel, with reduced pedal travel, a new pedal position, and a refined pedal feel help make braking feel, smoother and more confidence-inspiring in everyday driving, towing and hauling.
  • Smarter braking integration, supporting advanced driver-assistance features like Adaptive Cruise Control and Automatic Emergency Braking, while enhanced diagnostics help detect conditions such as brake fade or leaks sooner.
  • Cleaner, lighter and more refined system architecture, eliminating the shared hydraulic source for steering and braking to reduce complexity, remove weight, improve low-speed steering feel and support more consistent brake-control tuning on pavement and off-road.

Together, the new brake system gives GM's HD trucks a modern, confidence-inspiring braking foundation - one that reacts more precisely and works seamlessly with the truck's steering, chassis and driver-assistance technologies.

Drive Modes For a Variety of HD Scenarios

The 2027 HD lineup expands GM's coordinated drive-mode strategy so powertrain, steering, braking and chassis systems respond together to towing, hauling, highway driving and off-road demands.

Available modes include:

  • Normal - Everyday calibration for commuting and unloaded driving.
  • Tow/Haul - Tailors engine mapping, shifting, exhaust brake, grade-braking, EPS assist and electronic brake-boost tuning to support heavy towing and hauling with more stability and control.
  • Off-Road - Adjusts ABS, traction control and stability control to allow more wheel slip and side slip on loose surfaces, supported by EPS and eBoost tuning that cuts harsh feedback.
  • New Terrain Mode (ZR2 / AT4X) - A first for GM's HD trucks, enabling one-pedal off-road driving in 4HI and 4LO; lifting off the accelerator automatically applies braking for precise control on steep grades and technical obstacles.

Together, the expanded drive-mode strategy helps the 2027 HD lineup feel more tailored to the job at hand - giving drivers a truck that can adapt its powertrain, steering, braking and chassis behavior for everyday driving, heavy towing and technical off-road situations. The result is a more intuitive HD experience that feels composed, predictable and confidence-inspiring across a wider range of real-world conditions.

Trailering Capability and Technology

A 2027 GMC Sierra HD Denali Ultimate towing a trailer. Preproduction model shown. Actual production model may vary.

2027 HD models are engineered to offer serious towing, with capability of up to 46,500 pounds GCWR and up to 38,000 pounds max trailering on select configurations.

Core updates include:

  • Higher max available trailering capability, with properly equipped models offering up to 38,000 pounds max trailering and every diesel dually model capable of towing up to an available 30,000 lbs. or more.
  • More confidence with heavy loads, with revised chassis, suspension, steering and braking systems tuned together to help the truck feel stable, predictable and controlled when towing at or near maximum ratings.
  • Powertrains built to pull, pairing the available all-new Duramax 8.3L Turbo-Diesel V8 and enhanced 6.6L gas V8 engines with the Allison 10-speed transmission and updated shift strategies to help launch heavy trailers, climb grades and manage downhill control.
  • Available visibility technology for easier towing, including up to 14 available camera views such as Transparent Trailer View, Bed View and Surround Vision to help with hitching, lane changes, reversing and trailer monitoring.
  • Integrated trailering support from setup to the road, with the available in-vehicle trailering app, available Trailer Side Blind Zone Alert and available trailer tire pressure and temperature monitoring helping drivers prepare, connect and stay aware while towing.

The 2027 HD lineup is engineered to make heavy towing feel easier, smarter and more secure - combining added capability with integrated technologies that help drivers hitch, maneuver, climb, descend and tow big loads with greater confidence.

Availability

The 2027 Chevrolet Silverado HD and GMC Sierra HD are expected to arrive at U.S. dealers beginning late 2026. MSRP and additional product information will be announced in future updates.

For more information on Chevrolet Silverado HD, visit Chevrolet.com. For more information on GMC Sierra HD, visit GMC.com.

1Based on latest available competitive information. Excludes other GM vehicles. Horsepower and torque ratings determined based upon testing requirements prescribed in SAE J1349®. Your results may vary.
2Assembled with US and globally sourced parts.

General Motors (NYSE:GM) is driving the future of transportation, leveraging advanced technology to build safer, smarter, and lower emission cars, trucks, and SUVs. GM's Buick, Cadillac, Chevrolet, and GMC brands offer a broad portfolio of innovative gasoline-powered vehicles and the industry's widest range of EVs, as we move to an all-electric future. Learn more at GM.com.

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