Winter Tires for 991.2 12x20 rims
 

(Cross Posted in 991 Forum) I am not going to by 19" rims for the winter - I am determined to find something that works for my 2018 991.2 GTS with 20" wheels. 305/30R20 Rear and 245/35R20 Front. I've seen some of you use 295's in the rear - I don't like that option. Tire Rack has SottoZero3's that fit the rear but not the front size. So the question is - are 255/35R20 an acceptable alternative??? I think the differences in measurements are Sidewall Height +.13" Section Width +.39" Tire Height +.26" Tire Circumference +.82". Thoughts????

At this time there is NO option for this car in matching OEM sized winter tires for a 20x11.5" wheel. Your best traction option is to use a skinnier 11" wheel and a recommended 245 / 295 tire combo.

If you are set on the factory wheels, then using the 255/305 SottoZero3 option is your best option. The 255 measures:

Rim Width Range...... 8.50 to 10.00
Measure Rim Width.... 9.00
Section Width........ 10.2
Tread Width.......... 8.5
Overall Diameter..... 27.0

The N rated 245 Pirelli 240SZ is only a few tenths off.

Rim Width Range...... 8.00 to 9.50
Measure Rim Width.... 8.50
Section Width........ 10.0
Tread Width.......... 9.4
Overall Diameter..... 26.9

I have not had anyone with your car do the 255 up front yet, so I am unsure if that bit of a difference in section width will give any clearance issues. Usually .2" is no big deal, but I cannot promise it. Taking a good look at the front wheel well should give you a pretty good idea if the clearance is there. The SottoZero3 will probably not give the steering performance of the N Rated 240SZ do to the difference in tread width.

Not sure I fully understand your last comment - but wouldn't the same concern with steering performance be there with a 295 vs. a 305 on the rear???

I mis-typed. What I actually meant was tread compound and design. The Sottozero3 is a more open-treaded tire than the 240SZ, The difference will be an increase in tread squirm with the SZ3, which may cause handling issues if mixed with 240. It's best to use the same compound and tread design all around.

Sorry for the confusion.

Two questions here, I have the same issue with wanting winter tires in the stock sizes for a 2018 991.2 gt3.

First, does Pirelli make a 305/30 in a 20” tire for the rear wheels? The Pirelli website is impossible and I don’t see that size on tirerack.
Next, I see that Pirelli now makes a 245/35 front for a 20” wheel in their sottozero series 2.

So, second question is if they do have the right size front, even if it in series 2, and they now make a rear possibly in series 3, while not ideal, it seems to me that that presents a workable solution and allows for stock sized wheels. There can’t be THAT much difference between the two sottozero series and ultimately this is a winter tire setup for the cold weather, I’m not taking this setup to the track.

Agree or disagree. Thanks in advance.

It's outside of Pirelli's recommended rim range to install a 305/30 on a 12" wide wheel. It's a very low profile tire, and you can't expect it to pull further apart than it was designed to go. Sottozero 2 and 3's are certainly better to be used together than the stock summer performance tire, but we can't guarantee there will not be handling issues, and we certainly don't recommend using the 305 on a 12" wheel.

Thank you Damon. I was told that the 295 would fit on an 11" wheel, and that the 305 would fit a 12". The current stock size tires on the GT3 are 305 rear on a 12" rim (michelin or dunlop), why would the pirelli sottozero be any different?

The plot thickens....

The OEM (N rated) tires are designed and approved for 12" Porsche wheels. Non N rated tires are not.