Walk into any truck stop, job site, or RV park and you’ll find truck owners arguing about one thing: which diesel engine reigns supreme? The debate between Duramax, Power Stroke, and Cummins has been heating up for decades. With 2025 bringing fresh updates to all three brands, there’s never been a better time to break down what each powerplant offers.
- The 2025 Cummins 6.7L Turbo Diesel delivers High-Output ratings of 430 horsepower and 1,075 lb-ft of torque for Ram pickups.
- Ford’s high-output Power Stroke produces 500 hp and 1,200 lb-ft of torque, making it best-in-class for raw power.
- The 3.0L Duramax inline-six offers smooth, quiet operation and frequently returns excellent fuel economy, often passing 30+ mpg on the highway.
Heavy-Duty Showdown: The Big Three Diesels
When it comes to heavy-duty diesel trucks, three names dominate the conversation: Duramax (Chevy/GMC), Power Stroke (Ford), and Cummins (Ram). For over two decades, these engines have defined what drivers expect from a turbo diesel.
For maximum towing muscle, the 6.7L Power Stroke in the Ford Super Duty lineup stands out. It cranks out a best-in-class 1,200 lb-ft of torque, making it the top choice for gooseneck and fifth-wheel towing. The standard version delivers 475 horsepower at 2,800 rpm and 1,050 lb-ft of torque at 1,600 rpm, allowing it to tow up to 35,000 lbs.
Cummins Inc. unveiled the new 2025 6.7-liter Turbo Diesel Pickup engine system for Ram Heavy Duty as their most advanced diesel pickup engine yet. This engine is optimized with a brand-new 8-speed transmission, providing improved power, responsiveness, and driveability. The 6.7L Cummins is a proven long-haul option trusted by heavy-duty users for long-term reliability.
The Duramax 6.6L V8 Turbo-Diesel found in Chevy Silverado HD and GMC Sierra HD offers a blend of strength, drivability, and comfort, especially when paired with the Allison 10-speed transmission.
The Light-Duty Diesel That Changes Everything
Not everyone needs a three-quarter-ton workhorse, though. While Ford and Ram no longer offer smaller diesel engines for their non-heavy-duty trucks, General Motors still has you covered with a 3.0-liter Duramax inline-six.
The 3.0L Duramax Turbo Diesel engine produces 305 horsepower with 495 lb-ft of torque paired with a 10-speed transmission. That torque figure beats every gas engine in its class and makes highway passing feel effortless. The Duramax diesel excels at 23/29 mpg (city/highway), tops in the Sierra lineup.
The Duramax is the go-to engine for those who regularly haul heavy trailers or work in industries like construction, farming, or landscaping. Its ability to tow up to 13,200 lbs and deliver diesel efficiency makes it the best choice for maximizing productivity.
Unlike the inline-6 Cummins or brute-force Power Stroke, the Duramax prioritizes drivability. The V8 design eliminates the rough idle common in inline engines, making it feel more like a gasoline V8 during daily driving.
Reliability: Which Diesel Lasts Longest?
In a recent study by iSeeCars, diesel-powered heavy-duty pickups took eight of the top ten spots for trucks most likely to last beyond 250,000 miles. The Cummins 6.7L is known to clock over 500,000 miles when properly maintained.
The 6.7-liter Power Stroke has a strong reputation, with many considering it on equal footing with Cummins and Duramax engines when it comes to long-term reliability. Where 200,000 miles on a gasoline engine may spell the end of its reliable service life, a diesel may have another 200,000 in the tank.
The 6.7 Power Stroke engine has proven to be a very robust engine. With proper maintenance, the engine will last hundreds of thousands of miles.
Picking Your Perfect Diesel Match
Your choice depends on how you’ll actually use your truck. Buy diesel if you tow frequently, drive long distances, or plan to keep the truck 7+ years. Buy gas if you use your truck for commuting, errands, or don’t want complex maintenance.
For buyers who want a half-ton truck with diesel benefits, the 3.0L Duramax in the GMC Sierra 1500 hits a sweet spot between capability and daily livability. In the Sierra pickup, this engine offers 305 hp and 495 lb-ft of torque. It’s also the most efficient of the Sierra’s engines by a country mile, with the EPA rating this truck at 25 mpg combined with rear-wheel drive.
Drivers pulling fifth-wheels every weekend or running commercial operations should look at the heavy-duty segment. Ram HD leads with the most powerful torque at 1,075 lb-ft and a new 8-speed transmission, while Ford Super Duty offers the highest horsepower at 500 hp in its High Output variant.
All three brands have earned their loyal followings for good reason. The Cummins brings legendary durability and a massive aftermarket community. The Power Stroke delivers brutal towing power for the heaviest jobs. And the Duramax offers refined daily driving with serious capability when you need it. You really can’t go wrong with any of them.
