Sam CS 05

Hi I am currently running the standard 255/55/18 wheel size on my 05 CS.

1- How wide of a tire can I put on without changing these rims?

2- How wide can I go if I get a new set of rims and still stay within Porsche specifications for Cayenne?

TIA,
Sam

GTS Jay

If you don't get an answer hear I'm sure a quick call to tire rack will give you your answer...

Mike in CA

Both Michelin and Pirelli, for example, list a 285 tire as suitable for 8-10" wide rims. Your 18" wheels are 8" wide so they would theoretically be ok for that size tire. Your speedo will be off as the 285 is a taller tire; going up one size to a 265 might be a better choice.

On the 2011 Cayenne the widest factory wheels are at 10". I don't know the size of the widest wheels Porsche offered on the Cayenne before that.

Sam CS 05

Thank you very much Mike. Your answer was very helpful. Do you think going with 285 tire on my current 8" rim will create any safety issues? the indy mechanic says as long as side walls are kinda straight it should be fine.
Sam

Mike in CA

The Tire Rack link below is an example of the kind of info you can find on their site, for all types and brands of tires. Just click on the specs tab. You'll see that for a 285/18 tire the recommended width is 8-10". Given our litigious society, I suspect Michelin wouldn't list an 8" rim as acceptable for a 285 tire if it wasn't safe. Personally, I might be inclined to pick a tire that had a little more margin for error on the rim I was using, but in this case that's just me being ****......not a safety issue.

http://www.tirerack.com/tires/tires....titude+Tour+HP

francars

I believe the widest tire was 295 on 21" wheels. These were optional on 06+ Turbo S models IIRC