Diesel Domination: GM's 2027 Duramax Steals Ford's Thunder!

General Motors has announced significant upgrades for its 2027 Chevrolet and GMC heavy-duty pickups, set to revolutionize the HD-truck business by claiming new bragging rights. A major highlight is an all-new Duramax diesel V-8 engine, along with several other notable improvements aimed at enhancing performance, towing capabilities, and overall refinement.

The centerpiece of these improvements is the completely redesigned Duramax diesel engine, which sees a substantial increase in displacement to 8.3 liters, a nearly 26 percent jump from its long-standing 6.6-liter configuration, which has been in use for over a quarter-century. This new Duramax engine delivers an impressive 555 horsepower and 1,230 lb-ft of torque, marking an increase of 85 hp and 255 lb-ft over the current Duramax. Crucially, these figures surpass Ford’s 6.7-liter high-output Power Stroke V-8 by 55 hp and 30 lb-ft, and Ram’s 6.7-liter Cummins diesel by 125 hp and 155 lb-ft, positioning GM at the forefront of diesel power in the HD segment. Given this substantial displacement, there is speculation that the new Duramax may also offer further growth potential in the future.

This 8.3-liter Duramax represents GM's first in-house clean-sheet redesign of the diesel engine. Engineered for extreme durability under heavy towing conditions, it features a compacted graphite iron block, forged crankshaft and connecting rods, and steel pistons. The engine is also equipped with a variable-geometry turbocharger, an air-to-water intercooler, and advanced cooling-system improvements. GM emphasizes that, despite its increased power, the new engine is designed to be quieter and more refined than its 6.6-liter predecessor.

In terms of towing capacity, the 2027 heavy-duty trucks maintain a maximum conventional trailer rating of 20,000 pounds. However, gooseneck trailer capacity sees a significant increase by one ton, rising to 38,000 pounds. While this new gooseneck capacity edges out the 2027 Ram HDs by 980 pounds, Ford still holds the overall trailer-towing championship at 40,000 pounds. GM’s trucks will continue to lag behind cross-town competitors in conventional bumper-pull towing, where Ram offers 23,000 pounds and Ford offers 30,000 pounds. It is important to note that towing capacity is influenced by more than just engine power, with suspension and braking playing crucial roles. Customers are always advised to consult the manufacturer’s towing chart for any specific truck configuration, as actual towing capabilities can vary significantly based on equipment.

Beyond the headline-grabbing Duramax engine, General Motors is implementing other significant enhancements to its heavy-duty pickup lineup. These improvements are substantial enough to warrant attention and contribute to the overall advancement of the vehicles.

One such improvement is a slight power bump for the base gas engine, a 6.6-liter V-8. Its output increases to 412 hp and 472 lb-ft, up from the previous 401 hp and 464 lb-ft. While not as dramatic as the diesel’s gains, this enhancement still provides useful additional power for gas-powered configurations.

Perhaps most significantly, the 2027 HD trucks will feature a new electric rack-and-pinion power steering system, commonly known as EPS. This is a groundbreaking development, as heavy-duty trucks have traditionally relied on older hydraulic steering systems, while EPS has become standard in cars, SUVs, and lighter-duty pickups. This marks, to the best of current knowledge, the first application of EPS to a heavy-duty pickup truck.

The adoption of EPS offers several key advantages. It eliminates the need for an engine-driven hydraulic pump and extensive plumbing, resulting in a simpler and lighter system. Furthermore, EPS consumes less power because, unlike hydraulic systems, there is no parasitic power draw when steering assistance is not actively being provided. This technology also significantly simplifies the integration of advanced driver-assistance systems, such as a proper lane centering system, although GM has not yet announced such a feature for the 2027 trucks. From a driver’s perspective, GM states that the new EPS system will provide increased boost, an improved on-center feel, and reduced kickback, contributing to a more comfortable and responsive driving experience.