I consistently get 16mpg out of my truck up until about the last 4-5 fill ups. Have not changed driving habits or anything, but I am dropping about half a mpg per tank, I'm down to 14mpg now. Truck is a 4.6 2wd with 152k miles. No check engine light and still runs fine. Ideas? My only guess right now is o2 sensors.

 

summer blend gas...

 

I would consider a tune-up if one hasn't been done recently. Plugs, coils (or new boots and springs if no CEL), clean MAF, clean throttle body, bottle of Chevron/Techron in the gas tank, fuel filter and O2 sensors as you mentioned and you should be good.

 

LMAO

 

No - I have never gotten fuel mileage this bad. Edit - I take it back, I have. While doing 80 with a trailer behind me.

Probably about a year or so ago new plugs, new fuel filter. Oil change within the last thousand miles.