Estimated MPG for Ford F350 Diesel w/373 rear end

I have a 2013 F350 4x4 Long bed crew cab dually diesel with 3.73 gears and I pull a 14,000 pound 5th wheel. I turn about 1600-1700 rpm at 58 mph in 6th gear, which is the speed that I tow most of the time.

Max torque comes in at 1600 RPM.

I believe both 5th and 6th gears of the trans are OD.

In terms of a tow vehicle, there is absolutely no way I would want 3.31 gears in my truck. Just my .02 opinion.

I full time and towed about 6,700 miles this year and another 3,500 'tourist' non-towing miles. I get 11-12 towing and I can get 20-22 mpg at 55-60 mph non-towing. 14-15 around town with lots of cold starts and short trips.

Tim

Didn't think you could get 3.73 gears in a SRW F-350.

3.73 gearing is only available with a DRW. The 3.31 is with a SRW. Do you want a dually or a single rear wheel, or undecided? With my 2012 dually I get around 16 in town and 17-18 on highway.

I have a 2014 f350 with that gearing and get 16.5 city and 18 hwy. I am easy on the gas pedal and use cruise control as much as possible.

It's really the power the engine needs to produce to go down the road. You can produce that power with fuel intake at either a slower RPM or a bit faster one.

The difference comes when you are using the power in a gear range. Assuming you reach your top gear at highway speeds, if you have shifted into high well before you got to highway speed, you will likely stay in high when a hill comes in front of you. If you live in flat land, go with the lower ratio, but if you want to not have your tranny shifting up and down, go with the higher one.

I really doubt there would be much difference.

On my 2012 I get 16 or so in mixed driving and 17-19 on highway. Tires make a difference I've found. I swapped to some semi-offroad tires and the mileage dropped by at least 1 mpg, maybe more. Changing to Goodrich All-Terrain T/A brought it back up. Strictly highway tires would probably help more. I have a 4WD which might shave a little off the mpg. Wheels are 18 inch.

I've seen people saying that the rear end doesn't make as much of a difference on these newer trucks because of the 6 speed transmissions. I don't know enough about this to agree or disagree with that.

Maybe .5 MPG on a good day