What is the average gas mileage for a Ford F-250 diesel truck?

There is no Environmental Protection Agency fuel-economy rating for the F-250, but Autotrader reports that diesel models are capable of up to 20 miles per gallon on the open road on the 2014 model. The Chronicle, an Australian publication, reported fuel usage of 18 miles per gallon.

A 6.7-liter Power Stroke turbo diesel V8 producing 400 horsepower and 800 pound feet of torque or a 6.2-liter flex-fuel V8 producing 385 horsepower and 405 pound feet of torque power the Ford F-250. The F-250 Super Duty variant has a towing capacity of 18,500 pounds and a payload capability of 7,260 pounds.