Does anybody have any experience in the sizes. I am concerned about the diameter delta and not creating any AH or TC issues or limp mode on track with the computer.

I run 315/345 Hoosiers with no issues. Trying to avoid or prolong a shift to 5th gear an NJMP tracks. I figure the car has enough torque to handle the increased diameter.

The 325 705 18 Pirellis are 27.7 while the 325 660 18 has a diameter of 26.1 (delta of 1.6). Hooisers are 25.6F and 26.8R so delta is 1.2.
Then there are the 315 680 18 Pirellis at a diameter of 26.8. Those with the 325 705 have a delta of 0.9.

Are other sizes better? Trying to keep the widest tread width too.

Thanks!

Ron