This past autocross season i ran 245/40 on my stock (18x8) wheels and they felt somewhat sloppy coming from the 225/45 with a stiffer sidewall. Im thinking of going back to a smaller tire and i had 225/40 in mind. So i was wondering if anyone had input on 225/40 on an 18x8 wheel. How will they perform? It that a good size or should i just stay 245/40? also considered 235/40? All help is greatlly appreciated. Thanks guys.

 

Im not sure if youre asking for regular street driving or AutoX, but im currently using 225/40 Yokohama S-Drives for pure street use. Aesthetically, they look better to me. The slimmer tires go well if you've got your susension lowered. Cant really say anything about performance differences since ive always stuck with this size.

 

Autocross i mean. That's why i chose the rx8 racing section.

 

Generally more tire is better in autocross.

I'll be running 255/40/17 square.

You could experiment with alignment settings to help improve your turn in (touch of toe out, more front camber).

 

I use 225/40-18 BFG Rivals on OEM wheels. Been to 2 autocross, 2 circuitcross, and 2 HPDE events so far. The handling is extremely responsive and crisp, and wear is good. I'm a firm believer in running the widest wheel width for the recommended tire range and not "pinching" tires onto narrow rims. When I step up from OEM, I plan on 17x10 and 255/40-17.


there are videos in my youtube link in my sig, all on this setup.