Most Ford F-250 Super Duty V8 Diesel truck drivers report an average of 15 miles per gallon fuel efficiency according to Fuelly.com. The lowest driver reported mileage was 9 mpg, and the highest fuel efficiency was 21 mpg.
Both the 2014 and 2013 Ford F-250 Super Duty diesel engine trucks average 14.6 mpg. The 2011 and 1999 models had the highest reported fuel efficiency, with an average of 15.9 mpg. For 2011, this average was collected from over 498,000 miles driven by 32 trucks. The 2003, 2007, and 2012 all also reported 15 or more mpg. The 2009 diesel Ford had the worst average gas mileage at 12.9 mpg.