We put three of the newest and most powerful diesel HD pickup trucks to a towing MPG test on the Denver 100. Contestants are a new 2025 Chevy Silverado HD Trail Boss with a 6.6L Duramax V8, a new 2025 Ford F-250 Tremor with a 6.7L Power Stroke V8, and a redesigned 2025 Ram HD Rebel with an updated 6.7L Cummins I6. Which one of these trucks will be the most and least efficient when pulling these 28-foot car hauler trailers.
This is one of the most demanding videos we have ever pulled off on the Denver 100 MPG loop. We are driving all three of these trucks with identical trailers on the same loop at the same time. This video would not be possible without a long list of partners. Huge thanks to Granger Warranty, Weigh-Safe Hitches, and Complete Trailers!
The trailers we are pulling are the new ATV 500 ROM 550 car haulers. They are long and pretty tall. Each trailer weighs around 5,000 lbs. These trailers are not very heavy, but it’s a great comparison nonetheless.
The 2025 Chevy Silverado HD 2500 Trail Boss is a mainstream off-road trim and it’s powered by a 6.6L Duramax V8 that is rated at 470 hp and 975 lb-ft of torque. It sends power to the wheels via a 10-speed automatic transmission and a 3.42-to-1 rear axle ratio.
The 2025 Ford F-250 Tremor Platinum Plus is a fully-optioned luxurious off-road truck that is powered by a 6.7L Power Stroke V8 with 500 hp and 1,200 lb-ft of torque. It sends power to the wheels via a 10-speed automatic transmission and a 3.55-to-1 rear axle ratio.
The updated 2025 Ram HD 2500 Rebel is a top of the line off-road truck that is powered by an redesigned 6.7L Cummins Inline-6 that is rated at 430 hp and 1,075 lb-ft of torque. It sends power to the wheels via a new 8-speed ZF automatic transmission and a 3.42-to-1 rear axle ratio.
After topping off with diesel and driving 119.5 miles for this extended version of the Denver 100 MPG loop, here are the results.
| Denver 100 MPG results | |
| 2025 Chevy Silverado HD Trail Boss | 11.99 MPG (-1.95 mpg) |
| 2025 Ram HD Rebel | 12.69 MPG (-1.25 mpg) |
| 2025 Ford SD Tremor | 13.94 MPG |
This is a clear win for the high-output Power Stroke V8 turbo diesel. It got 1.25 mpg better efficiency than the new Cummins, and 1.95 mpg better than the Duramax.
Please join Tommy, Kase, and I in the video below for all the details.
