After exhausting research options that I know of I have found some people have gone from the factory 255/55R18 to 265/65R18. But I haven't seen many other size options. This is specifically for the base coil spring suspension, NOT air suspension!

1) Those who have gone up to 265/65R18 where does the tire rub or where is it closest to rubbing?

2) If anyone has tried a different size, please share your tire size and whether it rubs.

I am most curious about maximum total diameter and am willing to downsize tread width in exchange. e.g. 255/70R18 which is .5" larger diameter than 265/65R18 but also .4" narrower.

 

With air suspension, you can make 265/65/18 fit maybe only slight rubbing at max lock. But, I'm not sure that size will fit with coil suspension. Maybe driving straight it would be fine, but if you're off-roading (I'm assuming this is why you want such a big tire), then you may run out of wheel well when the moving over obstacles. Air suspension in spec terrain mode really restricts tire travel.

 

Very minimal off road. The primary reason for the taller tire is because my wife wants a bro-truck (go ahead, laugh. I do!) but the Cayenne is just too good to sell/trade. So the compromise is a slight lift from taller tires.

Off-road use is limited to pasture, mud, and gravel - not serious trails.

 

Maybe I can ask another way: for those running 265/65R18s and coil springs, how much clearance is there between the tire and the upper ball joint?

 

265/65/18 just barely fits but never rubs. I have even rolled around on the loading level (what little the car will let you do before it returns up) and it doesn't rub on any height . Heck, I just drove 1200 miles on low level with them and it didn't rub. I have air suspension calibrated to the "correct" height. The truck looks great on them and it turns a lot of heads.

Don't try to go any bigger; the 265/65/18 BFG all terrain ko2 looks great, does off-roading well, and is surprisingly great on-road. I haven't done any rock crawling, but it does great on the beach and in the mud.