GrantG

Dunlop Race Maxx2 was also an OEM tire on that car.

GrantG

delete

GrantG

Its a little hard to tell. They do make the 315/30/21 rear in N rated (ND0), but not sure if for GT3 or another model. The specs show the rim range only going to 11.5" (GT3 wheel is 12"), but these specs aren't always accurate...



However, there is no N-rated front tire in the right size at all, so I would say not homologated unless Tirerack catalog is incomplete...

seatactony

I've asked a couple of dealers to check on PS4S and will report back when I get a response.

Carcam

Actually my dealer ordered them and will install them for me, thought it was a good idea since I wouldn’t be tracking the car. Which I would think would help. I think a claim is a reach since most everyone else changes the brand of tires on their other cars when they need to be changed. I can’t imagine law suits bc someone didn’t put original OEM tires back on their car and in our case they already come with 3 different manufacturers as it is.

Carcam

Tirerack has them listed and the Parts dept at my Porsche dealer checked and said they’d be ok if I’m not tracking the car. I could see track related concerns for sure.

GrantG

Yes, the car does come with 3 different choices of tires. But they are all N-rated to specifically fit the unusually wide GT3 rear wheels and to work with the unusual load of a 911 GT3. Porsche is explicit about having to use tires that are N-rated for the particular model being fitted.

I'm not suggesting that you'll die or that your insurance will disclaim liability, but there may be some risk associated with using something non-conforming.

GrantG

Tirerack does not have an N-rated tire for the front (just ND0 rated for rear - not sure if that is for GT3).

The tires may be fine - I don't know. But I am not sure why a tire that is unsafe on the track would be good to use on the street?

Dr. G

Unless I'm missing something, tirerack doesn't seem to have the stock Pirellis.

Chris C.

With all due respect, that's such a huge stinking load of dealer cr*p. As long as the tires are DOT (US centric) approved and in the right sizes for the rim who is going to penalize you??

I choose N0 tires when they're available, particularly MIchelins, but any name brand properly speed/load rated tire in the right size can work fine for street use. I've run PS4Ss on the track many times though they came later than my 991.1

GrantG

Porsche makes exclusively weird sizes that do not correspond to the same sizes made by other brands or even the same brand without the correct N rating. On the 991 GT3, the stock rear tire was a 305/30/20, but the OEM tire was as wide as a 325 tire with a shorter sidewall (so you can't even find a 325 tire with the correct aspect ratio). Other tires in the 305/30/20 size did not fit properly - Porsche does this to create exclusivity with its OEM tires - in actuality, this creates an unsafe situation if one ventures away from OEM tires. The 992 size is less of a "stretch" on a 12" rim, but still outside the recommended use.

Rmas99

in such case on 992 which ones are 100% "safe"?

Chris C.

Thanks, and I understand your POV, and that N-rated tires are specifically optimized for the car. There is definitely value in that if they have the sizes and stock

I use N-rated Ps4S on my 991 even though I believe they were never N-rated for that car.
By that logic my Bridgestone RE-71Rs are unsafe for the track and street, too?

You will not convince me N-rated are required for safe driving, so let's not debate endlessly here. Big statement to say a tire is unsafe vs less optimized.

Edit: I will give you that one should look at load, tread size, etc carefully if you choose to sub-in a tire that was not OEM for that car. I do, but shouldn't assume everyone does.

mqandil

I have tried initially the Cup2 tires which came with the car and car felt nervous on some backroads and steering with busy and required both hand to be planted on steering wheel. I immediately suspected the tires, so I installed my 2021 targa good year tires set, which I removed earlier as I hated them on the targa. They lacked grip and the ride was bouncy. Of course these are slightly narrower tires at 245F and 305 R, but surprisingly they suited the GT3 very well and especially on wet roads, and transformed the GT3. overall the car felt so much better on less than perfect backroads including surprisingly the Dry and wet grip which was my main complaint when they were installed on targa, and made the GT3 a pleasure to drive on these road and the car can be driven with one hand on steering wheel and all nervousness was gone completely. Then I proceeded by installing the Pirelli Corsa tires and these were so so good. They have transformed the car in every possible way on bad roads. No nervousness, almost all harshness is gone, and steering does not require both hands all the time as before. Said all that and from previous experience, I think these Pirelli tires would not Hold very long or very well on track, and the cup2 tires will be a must if you track your cars. Just been hearing reviewers and magazines complain about car following the grooves and ride is harsh, etc, and just wanted to point out, you could mitigate that with different tires if these things annoy you. This car is so good, and if you are not happy just pick another tire set and all love is restored.

seatactony

Thanks much. This and related threads/reviews explains why there have been so many reviews that reach polar opposite conclusions about the road composure of the car. I won't be tracking mine and will likely switch out to PS4S or Corsas on delivery if I end up with Cup2s (don't have a final production pic so I don't know what tires I have).