General Motors Co. in Detroit today revealed updates for its new 2027 heavy-duty truck lineup, which will launch this year on the Chevrolet Silverado HD and GMC Sierra HD.
Central to the updates are the automaker’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.
The all-new HD diesel architecture, designed around heavy-duty pickup customers, has a compacted graphite iron cylinder block and fully forged crankshaft, connecting rods, and steel pistons forming the foundation for strength and durability, according to GM.
It’s said to offer 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.
Its advanced cooling and turbocharging systems are 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.
The new diesel engine promises improved drivability with an integrated intake design, advanced combustion system, and crankshaft isolation hardware helping reduce noise and vibration while supporting a more confident HD driving experience.
It’s paired 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,” says Norman Peralta, executive chief engineer for global engine and battery systems at GM. “From the clean-sheet architecture and combustion system to the cooling, aftertreatment and transmission calibration, this is a powertrain built with heavy duty purpose.”
The new engine will be built at GM’s expanded DMAX facility in Brookville, Ohio, 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.
Other updates to the GM heavy-duty pickup lineup include:
- An enhanced 6.6L gas V-8 that 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‑
- 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,” says Mark Dickens, executive chief engineer for GM full-size trucks and SUVs. “HD customers don’t hold back, and neither did we.”
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.
In Related News: General Motors contributed $1.5 million to support the MiSTEM Network to advance innovation in science, technology, engineering, and mathematics (STEM) education in Michigan. The gift, bringing the company’s total support to $2.5M, is focused on preparing Michigan students for high-demand careers in STEAM.
“Our partnership with GM is an example of how public-private partnerships are helping Michigan thrive both now and in the future,” says Susan Corbin, director of director of the Michigan Department of Labor and Economic Opportunity.
“This generous donation will help Michigan’s students have access to diverse STEM career paths and an array of in-demand careers as they graduate, and our state’s employers will have the talent pipeline they need.”
The strategic investment is said to build the strength of a public-private collaboration among GM, the Michigan’s MiSTEM Network, and MTEC SmartZone to build “dynamic learning environments” that connect students with real-world and in-demand industry experiences.
“Investing in students is investing in the strength of our communities,” says David Massaron, vice president of infrastructure and corporate citizenship at GM. “Through our partnership with MiSTEM, MTEC SmartZone, and communities across Michigan, GM is helping connect classroom learning to real-world experiences and equipping students with skills to pursue opportunity and shape a bright future for themselves,”
For more information, visit the MiSTEM Network, GM Corporate Giving or MTEC SmartZone.
