So when I put my truck into neutral while I'm driving downhill to save gas or stopped at a light or something, my fuel gauge goes down about an 1/8 of the tank. Sometimes more, always done this since I bought it but I don't have any problems with fuel being pumped. Any ideas?

 

Does it do it with a full tank?

 

Completely full? I'm not sure cus it's hard to tell when it's filled to the top, which I hardly ever have it that filled but with any amount of gas it does