2015 Ford F-350 vs. Ram 3500: Highway MPG Comparison [Video]

2015 ford f-350 super duty dually 4x4 is filling up with diesel for highway mpg economy test.
2015 Ford F-350

The 2015 Ford F-350 Super Duty Crew Cab King Ranch 4×4 is next up to take the highway mpg test. It’s being compared against the 2015 Ram 3500 HD Crew Cab Laramie Longhorn 4×4.

The Ford is propelled by the 6.7L V8 Power Stroke engine that makes 440 horsepower and 860 lb-ft of torque. The 6-speed automatic transmission sends the power down the line.

These two trucks are as closely matched as we have had. They are comparably equipped and have nearly identical weights. The Ford is actually 80 pounds lighter.

They were tested on the same day and same route (back to back). We used the same diesel pump. MrTruck.com (Kent Sundling) filled up both trucks himself and also drove the identical loop in both of these duallies.

The route is approximately 21 miles north-bound and 21 miles south-bound on the stretch of I-25 north of Denver, Colorado.

The trucks were towing the same LoadTrail flatbed tilt-trailer with the 1968 Ford Bronco on it. The total trailer weight is 7,250 lbs.

Dually HD Diesel – Highway MPG

 2015 Ford F-350  2015 Ram 3500
Model CrewCab 4×4 King Ranch CrewCab 4×4 Laramie Longhorn
 As Tested $ $67,810 $69,910
Engine 6.7-liter V8 6.7-liter I6
Transmission 6-speed Auto 6-speed
Power (hp / lb-ft) 440 / 860 385 / 865
Axle Ratio 3.73  4.10
Test Load (trailer + ppl) 8,250 lbs 8,250 lbs
 Ambient Temp F 66F 63F
Route (mi) 43.6 43.6
Elevation Avg (feet) 5,100 5,100
Highway MPG  12.36  14.20

Check out all the details in this TFLtruck mpg test video.

Andre Smirnov
Andre Smirnov

Andre Smirnov is a life-long automotive enthusiast, writer, reporter, and software engineer. He has been a contributor at TFL since 2011.