I was wondering if any one eles had this problem. On my 04lly was getin 19-20mpg now i get 10-12mpg. I have chaged my fuel fitter no chage. I will be putin it in to the shop for some paint work. what could it be? i have told my dealer about this but they havint found Any thing. any suggestion? thanks

Could be injectors. They should check the balance rates.

Another thing to consider is you will be running winter fuel now. You will not get as good of fuel mileage on winter fuel and you are probably warming it up more which also greatly reduces mileage.

Could be injectors. They should check the balance rates.

Another thing to consider is you will be running winter fuel now. You will not get as good of fuel mileage on winter fuel and you are probably warming it up more which also greatly reduces mileage.
I asked them to do the balance rates they said they could not do it unless they found a problem some where else; where they had to check them. I dont understand what thats all about if i told them i get bad mileage you would think that would be a reason to check them. when i got the truck it got good mpg the frist 2 months then after that down hill so i dont think its the winter thing. not sure though.

Thats definitely odd..I had a brief period like that then it rebounded? Things have been fine lately. I got some bad fuel...at least I think....when I was up north and got 14 mpg highway. Gradually dilluted that fuel out and since back in virgina and fueling up with the 45 cetane things are back to normal. Strange to say the least. Try some stanadyne and see what happens. You haven't been fueling up at a Shell have you? I have found that their fuel sucks for whatever reason.

It may be the paint repairs you stated, the air may not be flowing as well at it could. Wind drag will hurt mileage.