Who doesn’t like a good old-fashioned dyno shootout? The heavy-duty diesel truck market in 2025 is more competitive than ever. Ford, Ram, and Chevrolet have all been busy stepping up their game. At the heart of each of these workhorses lies an optional powerhouse diesel engine built for hauling, towing, and tackling tough terrain. While all three manufactures claim superiority in one discipline or another, it’s undeniable that it has been the horsepower wars that command the most attention.

Sure, the companies’ quoted flywheel power figures are fun to debate around the shop. However, it’s what makes it to the pavement that ultimately matters the most. To settle things once and for all, our friends at EDGE Products rounded up its trio of shop trucks, which included a 2025 Ram 2500 Heavy Duty, 2025 Chevrolet Silverado 2500HD, and 2025 Ford F-250 Super Duty, and strapped them to the company’s Superflow dyno. Let’s meet the Competitors.

2025 Chevy Silverado 2500HD

Don’t let power ratings fool you; Chevy’s Silverado HD has no trouble hanging with the rest of the diesel pack. The company introduced its latest generation of 6.6-liter L5P Duramax V8 engines in 2017. Undergoing constant improvement, in 2025 this engine produces a respectable 470 hp with 975 lb-ft of torque. This engine is available in all trims of both Chevy and GMC’s 2500HD and 3500HD pickups. Backing the engine is a 10-speed Allison automatic transmission.

2025 Ford F-250 Super Duty

Ford introduced its in-house designed 6.7-liter Power Stroke diesel V8 back in 2011. Now in its third-generation, Ford offers two variants of the engine: A standard-output and high-output. While the standard-output produces 475 hp with 1,050 lb-ft of torque, the high-output cranks out a best-in-class 500 hp with 1,200 lb-ft of torque.

The high-output Power Stroke is available in all trims across the company’s lineup and in both two-wheel and four-wheel drive. Backing the engine is a 10-speed automatic transmission.

2025 Ram 2500 Heavy Duty

Ram’s Heavy Duty lineup received a comprehensive refresh for the 2025 model year. Looks aside, the biggest news is found under the hood. Ram has replaced its two-engine strategy with a single high-output Cummins option for all models. This revised 6.7-liter I6 engine produces 430 hp with 1,075 lb-ft of torque and is available for all trims from Tradesman to Limited.

A new TorqueFlite eight-speed automatic transmission, ZF’s 8AT Powerline, replaces both former six-speed units. The additional cogs allow Ram to drop axle gearing to 3.42:1. With this, Ram claims the new trucks will offer noticeably improved fuel economy along with quicker 0 to 60 mph acceleration.

The Dyno Shootout Results Speak For Themselves

When the dust settled, the dyno shootout results painted a familiar picture. Unsurprisingly, Ford’s F-250 Super Duty with its high-output Power Stroke V8 came out on top producing an astonishing 504 hp with 1,181 lb-ft of torque. Ram’s 2025 6.7-liter Cummins I6 laid down 403 hp and 989 lb-ft while the Chevy’s 6.6-liter Duramax V8 produced 409 hp and 910 lb-ft.

The big takeaway isn’t necessarily the raw figures, rather how they compare to each truck’s rated output. It’s common knowledge that vehicle drivetrains will suffer a parasitic power loss of between 15 and 20-percent between the flywheel and rear wheels. In this test, EDGE found that the 2025 Ford F-250 produced a nearly 1-percent higher horsepower figure than its flywheel rating, with 98.5-percent of rated torque making it to the rear wheels.

A similar story unfolded with the 2025 Ram and its new Cummins engine, sending 94-percent of rated horsepower and 92-percent of rated torque to the wheels. Chevy’s Duramax landed closer to the accepted norm with 87-percent of rated horsepower arriving at the dyno roller, along with 93-percent of rated torque.

What this means is the subject of great debate. Are manufacturers derating these diesel pickups on purpose? Or are heavy-duty drivetrains getting more efficient? And how much more power can be unlocked by aftermarket tuning? All we know for certain is that it’s a great time to be a diesel enthusiast.