Ok, I'm guessing this can be done but can't find someone that has done it. I have a pair of the 19" OEM forged rims that I want to use on my '03 AT Coupe. My coupe came with the 17" wheels. I was going to use the 19" for the summer and through the 17" back on in the winter because they have All season tires on them. My question is If I put the 19" wheels on my coupe, how will the speedometer and other things be affected? Do you have to do anything to adjust this before driving on the 19's? I couldn't find anything about this on the forum. I heard you may have to make an adjustment through a scantool or something. I will be going from 235/50/17 and 225/50/17 to 245/40/19 and 225/40/19 tires.

 

No need to do anything.