20 inch rim question

[virkdoc]

Hi

Am planning to get 20 inch rims, but since the roads here in india are pretty bad was lookin at a higher sidewall.

Is it possible to put in 255/45/20 inch tires on the cayenne 20 inch rims?

Would they work fine? HAs any one ever tried em?

Thanks

Ron

[virkdoc]

Anyone?

[Loren]

The only 20 inch tire Porsche recommends is 275/40 R 20.

The Issues would likely be PSM and ABS faults (or erratic behavior) with different size tires. As well as possible wheel damage from the roads. So you might want to consider 18's or 19's (IMHO).

[clarksongli]

I installed 275/45R20s for a little extra sidewall. the speed difference was minimal, and got me into a category of less expensive tires (275/40R20's seem to be harder to find, must not match up with a mass producted GM/ford vehicle).

But i agree with Loren....just the little bit of India i have visited for work, go with a smaller wheel and larger sidewall package for sure. Most of the roads i was on were dirt. 18" with some meaty rubber would work nicely and provide plenty of pneumatic suspension in the tire.

[cayenneturbo]

I was thinking about going with 20" tire & wheel combo too, but different reasons. I have 19's on my turbo. Would I be sacrifing comfort if I go up to 20's.....would I be sacrificing performance if I go down to 18's? I'm trying to find a cheaper alternative to 19's, but some Cayennes with 18's the rims look oddly small and those I've seen with 20 or 21's look like they have no rubber.

[jagman1]

As a point of reference, I've always been surprised at how little the ride quality changes on my CTT when I switch from my summer 20" wheels to my winter 18" wheels. There is a difference, but it is very slight.

Also, don't forget that the side wall height is a percentage of width. A 275/40/20 tire means that the side wall height is 40% of 275mm. So, doing the math that means you have a 110mm sidewall height.

In your original post you said you were considering 255/45/20's. That equates to a 114.75mm sidewall height. A pretty insignificant difference (~5%).

[Andrei Marton]

In your original post you said you were considering 255/45/20's. That equates to a 114.75mm sidewall height. A pretty insignificant difference (~5%).

But a significant difference from 275 to 255. The traction and grip will get worse than 275. So , maybe you should tell us why are you going for this size ..

[Andrei Marton]

I was thinking about going with 20" tire & wheel combo too, but different reasons. I have 19's on my turbo. Would I be sacrifing comfort if I go up to 20's.....would I be sacrificing performance if I go down to 18's? I'm trying to find a cheaper alternative to 19's, but some Cayennes with 18's the rims look oddly small and those I've seen with 20 or 21's look like they have no rubber.

There is not much difference in comfort from 19 to 20. They feel like the same. Still very rigid. I have 255.50.19 for winter use and trust me , the 50 over 40 sidewall is not that much of a difference in comfort. Still, huge difference in performance, as high speed cornering is worse than 40 sidewall. So, YES, perfomance on 18" will be poor. I had one set of 18 winter tires and i could not make a sharp or even close to sharp turn, at any moment.

The 21 is good for performance, but those are design wheels. The OPTIMAL choice is 20, in 275.40.20, with high performance tires. I'm looking for Dunlop Quattro Maxx.

Here is why:

[virkdoc]

Thanks for all your help guys, I finally went with 18 inch rims and 255/55/18 rubber, ride is veryyy pliant even on broken roads.