Jim:

I'm considering the winter tire packages the Tire Rack is currently offering for the Cayman, but here's my dilemma...

I will likely go w/the 17in package, as I've always had good luck with the virtues of a smaller diamater rim (narrower width tire for a bit better traction and higher sidewall for more pothole margin).

Porsche's factory 17in rims are 6.5in Front (205mm tire) and 8.0in Rear (235mm width tire). The rims the Tire Rack is offering in the package are a one-size-fits-all 7.5in width. While I'm not particularly concerned about the 1/2in difference in the rear, the front tires (205mm) will be somewhat stretched on a full one-inch bigger rim. Is the Sport Cup Edition 4 available in a slightly wider rim w/out going all the way up to a 9 inch rim (I saw there was a 9in width available)?

Just would like to understand the guidelines for what mm width is truly compatible w/rim width. One inch being 25.4mm, it seems a bit much to stretch.

Thanks a lot
-Brian S.

I've been talking to Jim about this package. He says the tire size is what matters, and the car has no way of "knowing" what the wheel width is. In general, I agree with this, as long as the wheels have the right offset. Jim says he sold many of these for the Cayman last year, and had no complaints. On the other hand, Alan at Wheelworks thinks it will not handle well. He's probably right, to some extent. I don't plan on pushing the car real hard into corners with the winter wheels, though.

I'm a bit torn between this and an 18" package with Blizzak tires, which will have better
packed snow and ice traction, but probably a lot more noise, and higher chance of pot-hole damage, and maybe less deep snow traction.

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K-Man S

I posted this previously in another thread, but it applies here as well, I think:

I got my CS in July '06 with the intention that it would be my year-round daily driver, and have used it as such for 2 winters here north of Boston. I have 17" Cup Replica wheels which fit just fine. I did this in order to do a "minus one" set-up to use narrower, taller tires for better snow penetration and more ground clearance. Accordingly, my first attempt is 205/55/17 and 235/55/17 (F&R) Continental 810S Winter Contact Tires. This has given me the desired narrower profile, but still not as much ground clearance as I would like for penetrating snow depth. When these are gone (after this winter) I will look for an even taller tire, which will likely take me into small truck sizes. The Conti's are a fine "winter" tire but not very good in "snow" conditions. I will try a more aggressive snow tire - like the Dunlop Snow Sport line - next time.

Wheels and tires were purchased through Tire Rack and there are NO fitment problems. The only issue I had was trying to convince my sales person of what I was trying to accomplish with my set-up.

The CS is fine for most winter driving situations except for the big problem of traction control. Traction control is actually power reduction (limitation), so when you get wheel slippage in snow, and your proper reaction is to back off on the gas to regain traction, power is also cut back at the same time. So, you wind up with a "double" power reduction just when you need more of it to move forward. I have experienced situations where the traction control reduced power so much that I actually failed to progress forward in snow and starting up on a grade, and accordingly had to back -up or back down to start over. If the car came with a LSD there would be no such problem and it would be ideal in the winter.

In summary: if properly outfitted, the CS works fine most of the time in winter. If it's a real snow storm you are better off staying home until the roads are cleared (probably true anyway, but sometimes that's not the option available).

I looked into Continental's tire specifications on their website and the NO/N1 Porsche-Approved sport winter tires note an acceptable rim-width range of 6.5in to 7.5in for the 205mm tire. The 235mm tire also notes 7.5in w/in the acceptable range.

I guess I'm gonna go ahead and order the tires...plus Continental is throwing in an entry-level GPS w/an order of four Conti's. Maybe I need it, as I got lost heading to pick up my date a week ago. I was 1/2 hour late and she wasn't happy - but you can't stay mad at a guy w/a Cayman

-Brian S.

Hi Brian,

Sorry I missed your post. The 205/55R17 front and 235/50R17 rear will fit fine and work the best on the car in the winter. The two tires will both fit the 17X7.5 wheels and are well within spec for the tires.
If I can help just let me know. The sensors are due into us on 10/06if you wanted them.

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