Hey y'all, after owning a 7.3, Cummins 5.9, and 6.6 Duramax (in that order) I bought an 07 f250 king ranch fx4. Truck is immaculate with no history and is stock other than the exhaust and lift. I had it checked out by the local guru and he advised that I was getting a good deal on a good truck. Was informed in the dangers of idling too long with it by him and told that was all I should worry about as long as I don't use a performance setting on a tuner. I want to get a chip for it for fuel economy and towing, the performance setting will never be used. Any recommendations for best mileage in the under $450 range? Also anything to watch out for?