Just a thought to add to the mileage discussion. Keep in mind that rear axle ratio also has an effect on mileage. Mine is the standard 3:55 but if you have a higher two package your likely running deeper gears. Perhaps the 3:73 which would mean your engine is turning approx. 10% faster with the deeper gears. Although I would guess Ford usually installs the larger wheels with the deeper gears. Also, tire size which in my case knocked off at least one mpg by changing to 18" wheels and tires. Point is, you can't really compare MPG with a simple model year and engine. I think you could set a truck up for either towing or mileage. But not both.

 

You can with the 10 speed now. Final drive ratio of a 3.55 with 10 speed is now right around the same as 3.31 with the 6 speed, but the lower gears give the 3.55 better low end ratios than the 3.73 with the 6 speed. Mine is 3.55 and it is averaging 20.8 MPG over 45,000 miles. The 2014 I had with the 6 speed and 3.15 gears, was slightly less, somewhere around 20, but I will have to pull the data into a spread sheet and remove all the towing data to get the true average. The 10 speed is a game changer in trucks, as it give good fuel economy while still maintaining good towing ability without the need for really short gears as in the past.

 

From Salina Kansas to Northern Virginia 18.7 mpg in wet/snow mode and eco mode. 2020 superab xl with 22" wheels and roush supercharger. At one point I was seeing 21.2 mpg until I hit WVA.

 

2019 F-150 XL STX SuperCrew 4x4 w/ 3.55 axles @ 2,500 miles.
Currently seeing 19.9 on my commute into work. 17 minute drive, 9 miles. 2 miles 30mph country road, 4 miles 55mph highway, 2 miles 30mph city center, 1 mile 35mph country road. 361ft ascent, 420ft descent.
Been down to Boston, Chelmsford about 3 times I got just shy of 23 while I was on the highway. The trip overall I was seeing about 21.

 

Bought a used 2016, 3.5 lariat. A year ago, put 13,000 on it this year. Average MPG was 16.15 for the year.
I drive like 6 miles to work nothing over 35 mpg so honestly not bad.

 

My overall mileage over 40,000 miles on my 2018 5.0 FX4 is 17.4. 15 to 16 around town; 14 to mid 20's ( depending on wind conditions). The best I ever got was 27 with a tailwind. Of course with a 5.0 and 10spd. with 3:31 gears, my rpm at 80 is only 1700.

 

So, I just purchased my second 2015 3.5EB F-150. Loved my last one so much that traded my XLT in for a lower mileage Lariat. Both 5.5’ bed length w/same rims and dynapro 275-55-20 tires. The XLT had 98k miles on it and averaged 16.8 mpg with me driving very hard in city and on the freeway. My newer truck has 3.55 gears (not sure about my last truck though), 50k miles, and averages 15 mpg if I’m lucky while driving responsibly Two days ago I added 285/60/20 Copper XLT tires and a 2” leveling kit. I noticed my mpg is somewhere in the 13+ mpg range for combined city/hwy driving. Poor mileage... but she sure looks and drive good on these tires. I did notice a slight decrease in torque and power with the new rubber.

I don’t even want to know what my mileage is going to be when I hook up & take my 8000lb trailer out of town camping.

 

2019 Lariat FX4 502A SCREW , 3.5 Eco, 3.55 gear ratio.
Oct. 9, 2019 to April 21, 2020: 10,561 miles, 16.94 Avg MPG. Gas Pump Verified.

This was over MN Winter so occasional garage warm-ups from Dec.-Feb. before driving.
For reference, I also recorded instrument displayed MPG at each fill and that Avg. mpg was 16.87 --- my AFE Bias correction was input after first 3000 miles on the truck so I guess I got it pretty close.

 

@RossRR Thanks for all the work. I know first hand just how much dedication went into documenting those fill-ups. Wondering if you have a 36 gallon tank and if you ran it down close to Empty or being during winter filled once you reached half a tank?

 

A quick eyeball check of my book looks like an average tank fill was 20 gallons on the 36 gallon tank.