Maybe you should look for older truck to tow and get better mpg. My 97 7.3 Power Stroke gets had calculated 20 mpg on my 50 mile daily commute with 4:10 gears and running 50 hp chip. It now has 210K miles on it. Many older Dodges get similar numbers.I have no towing issues towing my 12,500 lb 5th wheel.
This Truck replaced my old TV which was a 93 GMC Suburban with 454 TBI, Average mileage on it was maybe 12 mpg, so for me the 20 mpg I am getting was a big plus and something I did not expect to get but am very happy I do.
I am also very fond of the Saturn SL cars with twin cam and clutch. I have picked up several used ones for $800 and had to put very little in them. Easy to fix and repair and will net you 40 mpg deepening on how you drive. My son uses one to commute with get 40 plus mpg, we paid $800 for this one. My Daughter has one with auto trans and has over 300k miles on it.
