Just a question. Do you have to have to have a dually or do you just want one? The reason I ask is in the right configuration you can get a long bed srw with a 12,400 GVWR and have 4500 plus pounds of payload. Based on what you say you are hauling it would more than do the job. I have a fifth wheel that was borderline between an srw and a dually so my last 2 trucks have been duals. My last truck, a 17 F350 KR dually with 3.55 gears, I kept for about 2 1/2 years and it did a great job. Most tows with the 5th wheel were 9 to 10 mpg and empty 13 to 16, why the range I never knew. I've had the 20 for 3 months now and I'm getting 16 plus just around town and 19 to 21 on the highway. I've only done one test tow with the fifth wheel for about 30 miles and the mileage was 11.4. I'm over 65 and have been told to stay home so not sure when we will get to do a longer trip. When I did the test tow I was amazed, let me repeat, amazed at the smooth ride and the seamless performance. I went about 20 miles at 68 mph and it stayed in 10th gear the whole time even on some not very steep hills. I got the 3.31 gears as the truck will mostly be driven solo but if my test tow is any indication I don't need anything else.

 

A random graph I pulled after a Google search is a fair indicator that the faster you go the more your MPG drops off. This came from an article at MPGforSpeed.com.



My F-350 with 3.55 gears and the 6.7L engine gets about 9.5 MPG when towing my 11K bumper pull toy hauler (aka the towable parachute). I keep to about 65 MPH, but when I get a heavy headwind it's not unusual for me to drop down to 50 MPH.

In the case of the OP, that little trailer and ATV in the bed shouldn't kill MPG that much. Low pressure in the trailer tires? Bad bearings? Sticky brakes? I pull my side-by-side on a similar size trailer and I don't think my MPG drops down that low.

 

4.10's is overkill for that kind of load - the RPMs can't be helping you.

 

im looking at a 2019 dually - what’s your payload? The one I’m looking at says 5373 is that about right?

 

2017 350 DRW extended cab 3.55 gears
Empty running 70mph on two 2,700 mile trips it averaged 13.2 mpg
Hauling an Artic Fox 990 camper 1,200 mile trip 10.8 mpg
Hauling the Fox and pulling a 20 foot aluminum boat on a 1,200 mile trip 8.6 mpg
Ford says that is as good as it gets is why it is getting a delete. It would be nice to know if those claiming 17 to 20mpg at using imperial or US gallons.

 

The higher numbers are likely coming from the 2020 trucks with the updated engine and the new 10 speed transmission.

 

2020 6.7 F350 drw 10 speed 3.55 eco mode

700 miles so far, no towing, mixed driving.

19mpg according to the gauge.

 

They're using full of ****.

These trucks get exactly what you posted.

And yeah, they make 1K lb/ft of torque but it takes 1/3 of that to blow all the soot through the DPF.

 

i know it’s not much of a test but the first 1000 miles in my 20 I really tracked mileage. The computer is nearly spot on and within .1 mpg of hand calculated. I’ve pulled my 5k lb steel gooseneck car hauler for over 550 miles of the first 1000 and it was showing 15.6, hand calculated at 15.5. The rest of that was right around 18. I added a lift and 285s on a Dually and now we’re in the 16-17 mpg unloaded range which is actually higher and I need to just update my tire size for an accurate representation

these trucks do very well on fuel compared to my priors.

3.55 DRW CCLB 4x4 Platinum

brett