The 2014 Ford F-250 with a gas engine may have an average miles per gallon in the low-to-mid teens, according to Autotrader.com. The Environmental Protection Agency does not test the fuel economy of heavy-duty pickup trucks.
The 2014 Ford F-250 with a diesel engine may average in the high teens to 20 miles per gallon. The average reported miles per gallon for the 2015 6.2-liter V8 gas engine model is 13 miles per gallon, with a range from six to 21, according to Fuelly.com users. The 6.2-liter flex-fuel V8 engine is the standard for F-250 and F-350 trucks. An alternative option is the 6.7-liter Power Stroke turbo diesel.