So we've our Ford for almost two years now. It's a 99 we bought used, it's all stock and we haven't really done anything to it, except small things that needed doing. Stuff like brakes, calibers, bearings. Nothing big. Our gas milage was 17ish empty 15ish towing. Well last month I decided to change the fuel filter and now our gas milage has jumped to 24.5 three tanks in a row! With city traffic and all the stop and gos. But our towing stayed at 15... granted we were towing a Couger on a trailor doing 85 in the mountains... so i guess thats good too. But my question is can changing a fuel filter REALLY make that big of a jump in gas milage? I only expected a couple miles extra. I was hoping to almost reach 20 not almost reach 25! (not that i should complain about that) It just seems really really wierd. The filter didn't look clogged or anything, just a little dirty. And then, if this made that big a difference does that mean I should be worried. If it was THAT clogged should I be concerned that it wasn't really working and that my injectors might now be clogged or damaged now too?