I have been searching the boards for awhile trying to find ways to improve my gas mileage. In doing so I have found numerous suggestions to replace the fuel filter. Is there really any merit to that? I was told by a repair shop that a dirty fuel filter cannot possibly decrease gas mileage. If anything, it will restrict the flow of fuel, therefore improving gas mileage. This logic made a lot of sense to me. Then again, I am no mechanic and don't have much experience with the effects of replacing fuel filters. So can anyone who thinks replacing a fuel filter will improve gas mileage explain why?