jlusby

Ok, so let me first start by saying that I always use the "configurator" on the websites like Tirerack, etc... but not finding many options that I like for a 20" rim. I have a 2014 Turbo S with stock 21" Turbo II rims. From what I am seeing I can run 19, 20 or 21, but not sure if I will like the look of the 19s, which is why I have been looking for 20s. I have been running a dedicated set of winter tires on my M5 and have always gone down a size and less width to help in the snow.

This is where my questions/confusion start....

According to this website - https://www.wheel-size.com/size/pors...urbo-s-48-eudm

These are my options:




Now for my confusion....

My stock rim is 10x21 ET 50, the 20" rim uses a 275/45/20 tire, so why wouldn't a 10x20 ET 50 rim work if this rim will use a 275/45/20 tire and has the same offset as the 21" rim?

I certainly do not want to buy something that won't fit so if someone can help explain this to me (or point me to a website that explains this more thoroughly so that i can understand I would appreciate it.

As always, thanks for the help!!

wkearney99

I went with factory Sport Classic 19", Part#: 958 044 601 54

This from the Tequipment website:
The rest of the year I'm running the 20" RS Spyder. Which, iirc, are 9.5 J x 20 RO 47 with 275/45 R 20.

The change to the 19" wasn't immediately noticeable with regard to ride comfort. It wasn't suddenly softer or anything. Cornering handling was reduced, of course, due to the combination of winter rubber compound, larger sidewall and narrower width. Over 50F and the Pirelli Winter Scorpion rubber was less grippy, but not radically so. The narrower track had noticeably better traction through snow, but we didn't get any considerable snowfall to really test it. Switching back to the 20's brought a return of added cornering control and a very slight change in ride comfort.

My advice? Stick to a simple design in gray or black. Switching back to the black Spyders brings along a lot more wheel cleaning due to brake dust. The five-spoke design of the Sport Classic is so much easier to keep clean, and the platinum color hides quite a bit of road grime and brake dust better than regular silver.

As for which rim should work, I'd stick with a size the factory already supports. This to avoid speedometer calibration issues or fitment in the wheel well. I believe the factory manual has some info: (it seems the '17 pages have more info than for '14, but everything should still apply)

http://porscheownersmanuals.com/2017...al/16/393/page

Here's my '17 GTS with 20" Spyders:


And the 19" Sport Classics:


The 19" fill the wheel well just as effectively as the 20's, granted these are not direct comparison pictures what with with the late afternoon winter sun angle vs mid-day.

jlusby

Thanks for the pictures and links. I agree about the more simple design and am looking at a very open design in black that is easy to clean. The interesting thing is that if I go to one website it says that the wheels will fit a Turbo (their drop down doesn't have a Turbo S) and I thought that both the Turbo and Turbo S had the red calipers (390 mm) so I can't see any reason why these wouldn't fit. I also believe that because the tire is a 275/45/20 which is one of the standard sizes for 20" then it shouldn't cause any calibration issues with the speedometer.

The only real difference is the 10" wide versus 9.5" but the offset is 50 which is the recommended offset for a 10" wide 21" rim....

So, curious if anyone else has any thoughts on this. I am looking at a used set which is part of the reasons for the questions since I have found two different sources of information that appear to have different information for the same rim....

wkearney99

I drive the hell out of my Cayenne and the 19 x 8.5" were not a cornering problem. Now, I didn't autocross with it, as I had my 20 x 9.5"s back on by then.

I'm guessing the 21" are 10" wide because of needing to handle the weight of the vehicle, not necessarily the traction. There's going to be a certain amount of carrying capacity required for something this heavy. Wider certainly has the potential for better non-Winter traction, but that also brings along potential of increase fuel consumption and tire wear/expense.

I'd likewise be curious to hear if anyone has offset info. Perhaps a post on the main Cayenne subforum might also help? Post a link in it back to this thread.

TomF

I run dedicated 21/295-35 Scorpions in the winter. They are great and have had no issues getting out of snow even up to nearly a foot. I also have Conti DWS in the same size which are great the other three seasons.

Just a note of caution- I cannot see how the 18" wheel would fit over the brakes. The 19 is almost too tight for my taste.

I suspect that 18" wheel/tire combo is an error.

Cheers,
TomF

jlusby

I believe you are correct in that the 18" not fit on the Turbo or Turbo S with the red calipers. Not to mention, it wouldn't look good at all when I switch from the 21" rims....

mikeearly

21's for the summer tires ... decided to go with 19s for winter tires..... haven't used them yet however....

a side question - when you go to the winter tires how do you handle the TPMS set up -- right now mine only shows 21 since that is what came from the factory ... so I guess a trip to the dealer will be in order this fall to have the computer set up for the 19s .. was wondering if this is something that has to get changed every tire swap or does the system get set up for BOTH??

Gages

TPMS settings can be adjusted from the menu.

The 21" Pirelli Scorpions are fine in the NY winters.

wkearney99

The factory 19" clear the red calipers just fine. 18" would definitely not.

Petza914

Are the red calipers on a Turbo and a Turbo S the same in the 958 generation? I'm not sure they are for the 957 since the Turbo S uses a larger 380mm rotor than the Turbo unless they just spaced the same caliper further out.

TomF

The 958 uses the same setup as the 957 Turbo S, unless it is equipped with PCCB.

Cheers,
TomF