Just drove home from oklahoma, i usually get around 550 to a tank on the interstate, Anyway i got only around 400 miles on both tanks of fuel! What gives? The only thing i've done is put that rail cap on and a guy wouldn't think that would cause that? I put my 315's on before i came down and got around 17-18 so its not that. Any ideas? i change fuel filters religiously so i doubt thats it. Oh yeah, one tank was fuel out my drag tank, and was was from a gas station.