Those who have 315/30/18s on your C5

[ModifiedC5]

I know there has been allot of speculation. The math works out to be a difference of about 4.6% (shorter than stock). But has anyone put them on and had any problems? Would you go to 295/35 if you had to do it all over again? Pls shed some light on the concerns of the impact of the shorter overall diameter as compared to stock dimensions on abs/active handling or anything else. Have you activated abs/active handling since you put the shorter tires on? Any issues? What front size did you go with? I am considering the 275/35/18 FR and 315/30/18 RR on 18x9.5 and 18x11, respectively.. Any insight is appreciated. thanx! :seeya [Modified by ModifiedC5, 10:24 AM 9/16/2002]

[Brutus0725]

Which tire maker makes 315/30/18's? I would buy them for my Z.


[Modified by Brutus0725, 5:30 PM 9/16/2002]

[GTB/ZR-1]

Modified,
You will want to keep the front tires around 96% as tall as the rears--or you will have traction/AH issues. If your tire heights do not have the proper stagger, the traction control will kick on during semi-aggressive turning manuevers. I know this because our Auto-X setup is 275/40-17 front and 315/35-17 rear(same overall height), and the car will not--other than a straight line--allow you to drive aggressively unless TC is turned off.
You will NOT have any rubbing issues if you go w/ the 315's. You will want to go w/ a shorter front tire if you decide to go the 315/30-18 route...
Hope this helps,

George


[Modified by GTB/ZR-1, 2:53 PM 9/16/2002]

[RCswish]

Which tire maker makes 315/20/18's? I would buy them for my Z.

that is probably a typo (315/20/18), but if you meant 315/30/18....Pirelli P-Zeros are the only ones right now.

[Brutus0725]

Thanks, that was a typo.. :crazy:

[ModifiedC5]

thanx George, what would be a more appropriate size in 18 to match the 315/30/18 rears?

[Modified by ModifiedC5, 7:27 PM 9/16/2002]


[Modified by ModifiedC5, 7:31 PM 9/16/2002]


[Modified by ModifiedC5, 7:41 PM 9/16/2002]

[GTB/ZR-1]

Ideally 275/30-18(just abt 96% of the 315's), but Pirelli does not make that size--yet... An alternative that may work is the 285/30-18, but it's a bit wide for a 9.5" rim, and it's abt 97+% height--although not optimum--it should work. I'm not sure if it will rub due to width--like I said, I have experience as wide as 275's for the front w/ no issues... Good luck

[motoracer]

While I am waiting for comp tires to arrive to put on for auto-xing, I had some used (285/40/17) tires put on the stock front wheels and there was no rubbing.


Since I was running 265/35/18 on the stock rear wheels, I could not drive past 55 without setting off the traction control.

Here is another question. If I put 18X9.5 all the way around is it possible to have 265/35/18 up front and 295/35/18 on the rears without any problems? I know it not optimal for the rear as a 295 calls for a 10 rim. But will it work?

[RCswish]

Sure, that will work fine. Go with a Supercar 295 on the rear as it has one of the more narrow tread widths.