I have 285 75 17 on 2005 f250 4X4 6.0l and have been running them for about 4 years. I was wondering if it would be worth the $100.00 to go to the dealership to recalibrate the PCM for the tire size. Also Im guessing it isn’t hurting the transmission either, just not sure. Thanks<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

 

Call around to some of the other dealers. My dealer did it for free. Took all of about 15 min. I later bought a tuner and now I can do it myself.

 

Most tuners have tire size input to set shift points, but they don't correct the speedometer. If you can find someone with an AutoEnginuity, that is one of the few tools that can do it.

 

Thanks everyone, I dont have too many friends so I will have to go the dealer route, lol. I just wondered if it would save me some gas milage or drive any different, Thanks again.

 

It won't affect your mileage or driveability, only where the speedometer points. I wouldn't do it if they charge anything over $50 and especially if they will charge to do it again if not accurate, it sometimes takes a few iterations to get it right on.