Correct Offset for 18x12?

[sleazy rider]

i am running a 19 x 12 rear c6 z06 spyder wheel with a 1/2" spacer mounted to 325/30-19 tires and it fits perfectly in the wheel well. the wheel off set is 59mm and the spacer is 13mm...can't remember if you add or subtract the spacer dimension from the 59mm dimension for the actual offset.

[Black Red '90]

Originally Posted by AndrewL

This may help you check your math: https://www.willtheyfit.com/

Thanks for the link, as it confirmed my math.


I recently moved & just got the car back in my possession to do some measurements. Unfortunately, I don't see how a 12" wide wheel will fit without modifications. I measure 21mm clearance (0.83in) between my current wheel and brake lines. I would want to keep some clearance, so I wouldn't go any more that an extra 0.5" inboard. Too bad there are no 305/315/325 width tires in 18" outside of track tires. I'm looking at a 12" wheel simply to fit a 335/30R18.