Quote Originally Posted by cray View Post
Your milage gets all whacked up on these newer trucks when you change tires for 2 reasons,#1 it changes the gear ratio with taller tires making it a taller gear. #2 and main reason is everything is computer controlled and based on speed reading related to engine RPM. Taller tires changes sped reading so computer is trying to regulate fuel and air based on those 2 readings plus it affects the shift points on your automatic transmission which affects milage. If your going to change tires to very much bigger tire need to go to dealer and have them change the revs per mile setting in computer. The computer can't figure that out on it's own. Or buy a programer and use it to set everything. Then you can reset if you change tires hunting season and summer.
When Big told me that when you felt the miss to just give it more gas and it would go away--I kinda knew what the problem was after I drove it a couple times after. Got the tires and it went away as I suspected. The problem wasn't a miss in the engine--but the tranny at a certain grade/load was searching for a gear. New tires problem solved. Another part was the exhaust which helped a good bit as well. This was due to not enough back pressure because the old muffler was rusted out on the inside. Even some "shops" don't realize this. Had one in southaven cut the mufflers off and ran straight pipe from cat to rear bumper on a full size Bronco I had--needless to say I had to do alot of engine tuning after the fact. although it was a 91 bronco-it was fuel injected and had alot of sensors and vacuum relays that made it run like crappie-until i tuned.