Truck Gas Mileage

My '85 C1500 6.2 diesel Suburban (700R4, 3.42 rear) was capable of 25, but it took long, fairly flat interstate to get it. The heavily loaded, tall roof Transit 3.7 in my sig has gotten 20, but ANY hills, traffic, headwind, or speed of over 60 just kills it, down to as low as 13 MPG!
We had our week long friend/family ATV trip up to Jericho in NH during Labor Day.

On the way home, I did about 14.5 MPG with my 3" Lifted F-150 on 33.5's pulling my 18' utility trailer with 4 quads on it.
I usually set the cruise about 72.

In reading these posts, I think most of you guys are doing all right! By comparison, my wife gets about 21/22 daily driving her Stinger.
Have two trucks, one for work one for not.
2017 Ford F150 2.7 ecoboost 18.5 MPG with 10 ply tires.
2020 Ford F150 3.5 ecoboost 18.0 MPG with 10 ply tires.
That's not bad at all.
I49 interstate here in La. has a speed limit ranging from 55 mph to 75 mph. I travel a lot on the 75 mph stretch, but still only travel at 65 mph. This gives me the best gas mileage (21-23 mpg).
i run 83 in the 75 zone. yeah she drinks at that speed but you make great time. especially with the 36 gallon tank. i go a solid 500 miles easy without ever stopping, even at that speed. if i run 70 i can make 700 miles easy.
I just came from CVS in town (16 miles away). I had to pick up my meds. Yesterday, I paid $2.82 for regular unleaded at WM. It was $2.99 today! 😳
'95 Dodge Dakota 2WD club cab, 3.9 liter V-6, 5spd manual; 17mpg in town, 20mpg on the highway @ 70mph. 245K miles on it w/OE engine, transmission, clutch, and rear end.
3.96 in N FL last weekend for 93. I use that in the 2.7. Well over $100 to gas up, had to run the card twice. 20.7 mpg the whole way back at 75, which is its running average.