F150 MPG decrease?

Hi it a word engine wear.

Check the tire pressure. Try a different brand of gas. Do an OBD2 code reader check. Everybody should have one of those.

Are your sensors in good condition?

Take the dead bodies out from the bed. The extra weight is causing the trick to run harder.

It may be stuck in open loop. The engine temp coming up to normal? Did he clean the idle control valve? Wrong plugs? Air filter installed correctly?

Nothing is tuneable on that vehicle. What did the mechanic do? Does he know how to read pid data and see if any sensor reads are off?

I always have to ask how mpg is being calculated and has anything changed in your life. 95% of people are not actually calculating anything. Last week $30 got me everywhere and this week it took $40 with no regard for the trip to disneyland on that tank.

Check the spark plugs, if one or two or not firing (wet) this will cause fuel mileage to go down.

maybe they raised the idle or something