If you go from a 235/70/16 to a 245/75/16 tire size is it necesary to have the computer reprogrammed for the new tire size. If you dont have it reprogrammed does it have any negative effect on the tranny or any other components of the drivetrain beside a speedo error?

Dave

 

Probably not, you should be okay. When your speed oreads 60, you will be going 63.1. That is not much of a change, I dont think it would warrent you buying a chip to correct it.

 

I just went from 235/70/16 to 275/60/17 and am not going to bother with a chip. My change was about an inch bigger, but not big enough to cause problems for me.

-Brian

 

Beastie,
Im going to a larger tire. I think my speedo will be reading fast not slower. I thought dealers reprogrammed computers for tire size and tranny shift points when going to a larger tire? I wasnt thinking about chipping it.

 

Your speedo will be slower than what you are actually going if you go to a taller tire.

 

Dealers CAN change the tire size inputs in your factory computer. Usually there are few size options in the computer for them to change to. Depends if you are change to a size that was offered that year on those trucks. Your making such a "small" change that it really will not affect your shifting points. Hope this helps.

-Brian