Why does my 150 only get 13 mpg when it used to get 17
When's the last time it got a tune up? Air filter? Fuel filter?
Has your outside dropped below 34 degrees? if so the system has enriched the fuel mixture to compensate.or it is possible the some of your sensors are out of specs.
Depending on where you live refineries have to switch to a winter blend as a certain portion of the year. Maybe they haven't yet and the cold blast may affect your mileage. If everything is within specs try running a tank full of non-ethanol and see if it improves during cold weather.
Looking for a Used F-150 in your area?
CarGurus has 214,895 nationwide F-150 listings starting at $1,000.
Search Ford F-150 Questions
Ford F-150 Experts