So I ran into a issue with the dealer when I took my car in for alignment and noticed I've change the stock 19" rims to a new 22" rims.

The original tire size was 265/50/19 and I went with 265/40/22. The overall total diameter increased by .92 which the dealer is now claiming can damage the transfer case. They noted the transmission has to work harder to spin the wheels when in fact I notice based on the specs, the transmission has to work less since Rev per mile decreased.

My question to all the forum members, should I pay much attention to the deal on what they are telling me or ignore it? Is there really a risk of damaging anything by going to a bigger rims which may increase the overall dimensions? I'm thinking if that was the case, no one will put custom rims/tires on any Porsche.

 

Less revs/mile = more torque through the transfer case.People will put custom rims/tires on cars - but they generally try to stay with the same rolling diameter. That avoids these sort of problems/concerns.

 

Any time you're debating tire size changes, it's useful to know the real stats. Various websites exist to help. I like using this one:

https://tiresize.com/calculator/

With AWD/4WD systems it's VERY important to be careful about tire conditions.

Why didn't you buy tires with at least the same overall dimensions?

I'm not sure there's a "look" that's worth the risk of blowing up the transfer case on something this expensive. Is the money wasted on the wrong tires so important as to risk a transfer case replacement, now very likely out of any kind of warranty? No, not for the inanity of "rollin' the 22's" But hey, your call.

 

you're suppose to run 285/35/22 or 295/30/22 if you go with 22" wheels.

 

I have been running 305 35 22 Pirelli tires (as do many others!) on my 2011 Cayenne Turbo with literally no issues for about 2 years now. 285 35 22 are too small, they do not offer much in the way of rim protection as my previous 2 bent rims will attest. For people with the stock 21" wheels they should run 295 40 21, Continental makes a Y rated all season Extreme DWS06 in that size. Your Cayenne's ride will be smoother over bumps without any real loss of road feel. And as an added bonus your speedometer will actually be much more accurate and no longer 3-5mph off anymore. As such nor will your miles driven be grossly overinflated, which is helpful for maintaining your warranty.

 

To the prior post, I know on the 955 they had a minor running issue on the inner wheel well at full turn that required slight modification to the liner. Have you turned the wheels full and visually checked for clearance? Thanks

 

On my 2011 Porsche Cayenne Turbo with the 305 35 22 when they were new there was very minor rubbing on the inner wheel fender behind the intercoolers on full wheel turn lock. Gradually over the last two years that has pretty much gone away, probably a combination of the inner wheel fender stretching a bit and the tire wear.


On my other 2012 Porsche Cayenne Turbo with the Continental Extreme DWS06 295 40 21 there are no rubbing issues though once the alignment was fixed. Even though the overall tire diameter is about the same as the 305 35 22, I believe the extra 5mm width less on each side of the tire makes the difference in the tire rubbing the inner wheel well or not.

 

I appreciate the insight. Do you happen to have a picture of the 295/40/21 mounted on your Cayenne? I don't want you to go out of your way, but if you have a picture I was curious. I presume it is not a noticeable visual difference.

 

Sure, I will do you one better. Here are pictures of both the 2011 with the 305-35-22 and the 2012 with the 295-40-21, both vehicles in Low (Sport Suspension) mode. Please excuse the brake dust!

 

Thanks. It actually looks like the 305/35 has more room than the 295/40 or maybe it is the way the front wheel is turned on the 295/40 that it just looks that way. I expected the opposite based upon your post and the actual tire size.

 

Actually I was wrong, the 295/40 should extend slightly closer to the wheel well as the picture shows.

 

They tires are actually very close to being about the same diameter, (just over a tenth on an inch difference) and closeness to the the respective wheel wells. I will say that if you look at the 4th picture you can see that the 2012 vehicle with the 295's is equipped with the wider fender flares which may alter your visual assessment as well.


Here is a more precise comparison on the tire diameters and other measurements. I now use this site all the time for tire measurements, I originally got the link from RenaissanceMan :


https://www.tacomaworld.com/tirecalc...5r22-295-40r21


Also, the vehicle with the 305's the wheel is turned slightly outward to the left, with the 295's the wheel is turned slightly inward toward the right. I apologize for not straightening the wheels on both prior to taking photos first for a better visual analysis.