- 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.