I run ASP so I am not dead sure about this. I have been having a debate with some other auto crossers and hoped some of you that ran stock classes could settle this. To run stock class, do you have to run the OE tire size? Or is there some allowance for change like in other classes? You must run stock wheel size, right?

 

Stock size with at most a +/- 1/4" variance on factory offset.

You can use any size DOT tire that will fit on the wheel.