Tire size for 18x10 C. lightweight - 986 Forum - The Community for Porsche Boxster & Cayman Owners

insite · 08-01-2007, 09:11 AM

i'd go with a 245/35 up front and 265/35 in back. the 285's get expensive and add to the understeer. the 245 / 265 combination is really neutral.

RandallNeighbour · 08-01-2007, 09:54 AM

Adding some 5mm or 7mm spacers in the back will heighten the aggressive stance of your boxster. I did it when I bought the same rims.

http://www.iwantaporsche.net/TOD/PICT0278.JPG

Adam · 08-01-2007, 10:02 AM

265's are pretty skinny for a 10" wide wheel. 265's are meant for a 9" wide wheel. Might look kind of funny or provide funky wear/handling issues....I would go to at least 275's, but 285's is usually the width you want with a 10 in wheel. You might get some more understeer though as Insite mentioned, but are you tracking the car? If not that would be a non-issue.

timothy · 08-01-2007, 10:36 AM

Seems when it comes to tire fitment everyone has a different opinion. I am not tracking the car but might try sometime.

So far nobody disagreed with 245/35 up front. Maybe 275 is a compromise on the rear. Is that a 275/35 or 275/40? Still open to other opinions. Thanks.

Adam · 08-01-2007, 10:59 AM

Quote:

Originally Posted by timothy

Seems when it comes to tire fitment everyone has a different opinion. I am not tracking the car but might try sometime.

So far nobody disagreed with 245/35 up front. Maybe 275 is a compromise on the rear. Is that a 275/35 or 275/40? Still open to other opinions. Thanks.

The stock 18's on the boxster had 40 up front and 35's out back. I would stick with that tire side wall height. You could go 245 up front.

insite · 08-01-2007, 12:09 PM

Quote:

Originally Posted by Adam

265's are pretty skinny for a 10" wide wheel. 265's are meant for a 9" wide wheel. Might look kind of funny or provide funky wear/handling issues....I would go to at least 275's, but 285's is usually the width you want with a 10 in wheel. You might get some more understeer though as Insite mentioned, but are you tracking the car? If not that would be a non-issue.

a 265 is fine on a 10". looks ok, too (that's what i run).

easyc · 08-01-2007, 12:31 PM

On my 9.5" OEM carrera lightweights, my 265 Toyos were pretty stretched... My new 275's protect the rim much better... you have to be careful with 285's as some may not fit. I also run 245's in the front, but they do rub under full lock... but im on PSS9's. Go with the 235 or 245 in the front and 275 in the rear you will be happy...

porsche986spyder · 08-01-2007, 01:08 PM

I have the 285/35 in the rear with no issues. I did have the 265 in the rear on my 10" wide rims and it did cause the outer lip to hang off by 1-2mm. Looks stupid this way and does seem to catch more rock chips and debri this way. If I were you I would go with a 275 or 285 in the rear. The stock tires of 265 are just NOT wide enough. For the first 9 months I had the 265 tires on my 18x10 and every time I went to a car show someone would point out that the tire really doesn't cover the width because you can clearly see the lip hanging out futher from the tire. Like I said it looks bad and even discount tire told me a wider tire would be better. The 265 tires will also were down on tread allot faster on the outsides.

timothy · 08-01-2007, 01:53 PM

Thanks everyone for the advice. "Gary" from Tire Rack practically fell out of his chair when I told him the recommended sizes.

I am leaning 245/35 and 275/35 since a 285/35 side wall sounds kind of tall. RUF will be doing the tires / wheels, alignment (hey where did that concrete median come from!), and 60k service, so I also emailed Hans for advice. I'll add his response to the thread for future readers.