I've been fortunate to locate a set of pristine OEM Rays 18" Track wheels. The stock tires were 225 fronts and 245 rears. Do any of you guys have wider front and rear tires on these wheels? I was hoping to put 235/45 on the front and 255/45 or 265/45 on the rear. I don't want any tire bulging or create any adverse driving conditions. If 265 is too wide for the 8.5" wide please give me your opinions. Thanks.

 

I suggest the OEM with plus 10 mm.

 

245x40 front and 275x40 rears are common.

 

I don't see how you can squeeze a 275 mm wide tire on an 8.5" (215.9mm) wide wheel. I figured out how to use this site after making my post. I can do 255 and possibly up to 265 without any major headaches.

http://www.1010tires.com/TireSizeCal...?action=submit

 

255/45 on the rear is perfect, if you look and the manufacturer specs on those compared to the 245, the ride height is almost the same, and the revs are very close. I would like a 235/45 for the front, but that size is almost impossible to find, so I will stick with the 225.

John

 

lots of autoX ppl use 275's on the OE 17" rims (if you're in stock class, you can't change your rim diameter or width dimensions)...so lots of ppl put on 275's - performance is good...but the tire can looked buldged a little bit.

 

Correct, and preferably a 255. I have seen a 275 also, and felt it was bulged. It goes against all tire distributors suggestions.

 

I'd run 245/40/18 on the front and a 245/45/18 in the rear. It would provide the most neutral handling characteristic, and as long as your tire choice is a sticky one, you'll probably run just as quick as somebody squeezing 255+

I just looked at tire choices, the Bridgestone RE-01R and the Azenis RT-615 is available in a 245/40/18 and the 245/45/18

An even better tire if you want to stick with street selection is the 255/40/18 Yokohama AD07 which is $290ea from tirerack.com and have better grip than the RT-615's...

 

I use 275 for auto x and 255 for street. This seems to work pretty well.

 

What data supports your claim that the Yoko AD07 has better grip (and in what sense) than the RT615? Thanks...

 

Local SCCA WDCR autocrossers and a few NASA time trial guys.

 

Thanks to everyone for giving me your opinions on the rear tire width for the Track 18" OEM rear wheel. Actually I have found quite a few makers of the 235/45/18 and 255/45/18 size tires. I'll post some pics next week after I get the wheels mounted to my Z,

 

Thanks for the info. The 180 tread rating keeps me in the street class, also, which is good, but they don't (yet?) make a 275 in a 17", only 245 or 255 max. Boo. I might try their 295/30/18 for my street tires. They are about 2x over the RT615s though!

 

You'll like them.

 

275/40/18 On the back on my stock 06 rim. It fits. The tire has never fell off or came off of the bead.

 

My roadster came with 18x8 inch rims and 245 wide tires from the factory before going to 20x10 with 265 wide in the rear.

 

Put your 275's on al 4 corners. I have an 03 and bought a 2ed set of stock rims. I mounted 275's on the 4 stock rear rims when going to Hpde. This gives me the best turn in performance on the corners.

 

I've seen people do that as well. It's a good idea since you can get them so cheap. Only downside is that the stock wheels are heavy castings...I do like 275s on all 4 myself, as I run them on 17x9.5s.

 

275 on all 4 for auto-x would be great

 

275/35 front and 275/40 rear would be optimal on an 18" wheel wide enough to support it.