245's or 235's on 8 " rims?

[DavidM938]

Hello Brian it's finally time to replace the 215/45/17 RE 71s that are on my 17 x 8 6UL rims. The car is a 2013 Club PRHT used almost entirely for Miata club events and autocross; it is not a daily driver, and I have my OEM rims and Michelin Pilots if I need total a long trip. No longer a competitive car just a fun one. Should I go to a 245/40 (which gives me lots more choices and are less expensive too) and will that size even fit without rolling the fenders? The car sits nearly 2" lower than stock with Progress springs and Koni shocks and an autocross-type alignment with a fair amount of neg. camber. It seems the best overall 235 is the Dunlop Direzza and and I'm assuming that is plug and play on my set-up. Is there any compelling reason to go to the 245s? Thanks
David in Nashville

[Brian]

We have done 245/40 on 17x8, but it feels sloppy. That 245/40 would be faster for autocross than 235/40, it's just the nature of autocross as you know that we stuff extra tire on there to go faster despite fact it feels sloppy. Website wheel section HERE says max fit under stock fender lips is 235/40 and we are sticking to that position. So, if you don't want to worry about the potential rub my suggestion is the 235/40 size (Dunlop makes a good 200 treadwear, NITTO makes a good track tire in that size, Toyo has a full race RR in that size). If you want to run the Rivals/RE71R in 245/40 my suggestion is roll those fender lips to avoid tire yanking down the lip and breaking the paint.

[DavidM938]

thank you, I'll probably get the Dunlaps and just enjoy the car.