i just joined this site, hoping to get some information. i dont own a diesel yet but i am planning on buying a used 4x4 dodge crew cab when i rotate back to the states. im wondering what upgrades yield the best gas mileage and engine longevity? i am planning on getting a performance intake and exhaust along with a tuner but dont know which brand to go with or what other mods i should be looking at. any information will help so i can budget for them.