Woodman207

Hi all!

May I get some assistance on if the 718 18inch fit on 987.1 Boxster please.

Thank you!

audi49

Front wheels match the 987 18” wheel for offset.
Rear wheels inner rim will be 3mm more inboard than the 987’s 19” (most inboard of the 987 stock sizes) and about 12mm more inboard than the 987’s 18”. Should verify that this isn’t a problem.
The tire sizes here have higher sidewalls than the 987 and so would suggest to go to the 987 tire sizes.

Woodman207

Thank you! I assume the hub size is also the same? Thank you again!

Aussie skypig

Where is the “offset” actually measured? From the face of the wheel where is contacts the hub to the inner edge of the rim, (outside where the tire bead sits) ? Or ?
I think I read, that the Cayman 987.1 with 18” wheels, has a front offset of +57 (mm?) and a rear of +43 can anyone confirm?

audi49

Here is offset explained. Our wheels have a positive offset. And so a larger offset moves the inner rim inward further, e.g.

https://www.lesschwab.com/article/wh...el-offset.html

audi49

yes center bore is 71.6mm for both

Aussie skypig

Thank you. Perfect.

I guess, going to wider wheels, one would generally have to choose wheels with less positive offset to retain clearance from brakes/suspension. (Not that I’m thinking of going wider)

Can anyone confirm the offsets I quoted are correct for a stock Cayman S 987.1?

old man neri

I'm not sure if it matters but if you are looking for a set of winter wheels and tires there are cheaper, and probably better, options out there.

FlipE

Somebody will correct me if I am wrong here but I believe that 987 Cayman cars had a standard wheel set that was 17" and narrower than the larger-diameter wheels. I would think that these 17" wheels would be good for snow tires.

The 17" wheels were standard for my 987.2 Cayman, but my car came with the wider optional 18" wheels that were apparently standard on the Cayman S in 2011.

old man neri

Ya, I currently have Boxster 17s on my 987.2 S for winter. 17s give me more sidewall, better tire selection, and cheaper tires. I am happy going to 17s during the winter.

Aussie skypig

I found a parts catalog. And the above offsets are correct.
​​​​​​​
From the same resource, the optional wider 19” wheel offsets.
Porsche option 19x9.5 +46
Porsche option 19x10 +42

old man neri

I found this website to be fairly accurate when trying to get a general idea of what car came with what wheels/tires as options.
https://www.wheel-size.com/size/porsche/cayman/2007/