Here is how the newest 2020 HD off-road trucks compare on road trip fuel economy. We take a 2020 GMC HD AT4, a new Ram Power Wagon, and a 2020 Ford Tremor on a 330+ mile road trip from Colorado to Moab, Utah to see how they do in daily highway driving.
HD Off-Road Truck Road Trip
Fuel efficiency may not be the first thing that comes to mind when talking about huge heavy duty trucks, especially off-road focused trucks. Still, these are heavy hauling luxury trucks that must be driven on a daily basis.
All three of these trucks are all stock with zero modifications. They are all equipped with many luxury options. Here is how they did.
GMC Sierra 2500 HD AT4
The 2020 GMC Sierra 2500 HD AT4 is powered by a carry over 6.6-liter Duramax turbo-diesel V8 that produces 445 hp and 910 lb-ft of torque. The engine is mated to a new 10-speed Allison automatic transmission. The rear axle ratio is now a 3.42 for all 2020 diesel models. You can also configure this truck with a 6.6-liter gas V8 that is mated with a 6-speed automatic and a 3.73 rear axle.
Ram Power Wagon
The Power Wagon is the only truck in this group that does not offer a diesel engine, as such it is powered by a carry over 6.4-liter HEMI gas V8 with 410 hp and 429 lb-ft of torque. For 2019 and beyond, the big HEMI is mated to a new 8-speed ZF automatic transmission. This V8 is also equipped with cylinder deactivation that allows the engine to run on four cylinders under light load. Although, the rear axle ratio is still a 4.10, which is not conducive for great efficiency.
Ford F-250 Tremor
This particular 2020 Tremor is equipped with an updated 3rd-generation 6.7-liter Power Stroke turbo-diesel V8 with a rating of 475 hp and 1,050 lb-ft of torque. The diesel is mated to a new 10-speed Ford automatic transmission. This particular truck is spinning a 3.55 rear axle ratio. You can also configure a Tremor truck with a 7.3-liter gas V8 with a 10-speed automatic and a 3.55 rear axle. The new 2020 Tremor is also equipped with an “Eco” transmission mode that may or may not provide any advantage during a highway speed road trip.
The Tremor is rolling on 35-inch tall Goodyear Duratrac tires (largest in the segment), which will likely hurt the efficiency.
This road trip MPG is also part of our bigger 2020 Gold Hitch off-road competition and our Moab, Utah off-road comparison.
Video spoiler alert: Here are the MPG results for the three trucks.
- Ram Power Wagon (Gas): 14.5 MPG
- Ford Tremor (Diesel): 19.2 MPG
- GMC Sierra AT4 (Diesel): 19.8 MPG
I also ran a new 2020 Chevy Silverado 2500 HD crew cab 4×4 with the Duramax diesel and a 10-speed automatic on a long 1,000 mile road trip. I got a result of 19.9 MPG that time. It appears that the AT4 off-road package does not negatively impact the highway efficiency of the new GM HD truck in any significant way.
Both the Power Wagon and the Tremor also showed good and fairly impressive results. The new 6.7-liter Ford diesel is the most powerful production pickup truck engine out there, but it still delivered impressive 19.2 MPG on this trip.
Gas-powered truck are less efficient than diesels, so the Power Wagon result is understandable. The gas-powered trucks are also less expensive to purchase. The fully-optioned Ram you see here has a sticker price of around $68,000. The other two diesel trucks had prices hovering around $78,000. That is a big $10,000 difference.