When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I ordered a set of Michelin Pilot Sport 4S in RS size (265/35/20, 325/30/21) and in N spec. I plan on use these on the street or when the track gets too wet. I use a set of Forgelines with Dunlops for dry track duties.
Tires arrived Monday, and the fronts are a smidge wider than stock Cup2, but the rear is more than 20mm narrower ! Tire Rack listed the 325/30-21 tread width 11.5" for the PS4S and 12.8" for the Cup2.
Hmm interesting. I'm literally going through this exact process right now thanks for posting. I'm wondering about upping the rear size? Only seeing a 355 is next up after 325 which seems a bit much. What did they look like mounted I wonder? How you liking them? Im in Houston also I am going to give the mobile tire guy a try and see how it goes everybody is saying they are great!
Hmm interesting. I'm literally going through this exact process right now thanks for posting. I'm wondering about upping the rear size? Only seeing a 355 is next up after 325 which seems a bit much. What did they look like mounted I wonder? How you liking them? Im in Houston also I am going to give the mobile tire guy a try and see how it goes everybody is saying they are great!
They look pretty stretched mounted on stock wheel. I have not mount them on the car yet.
If you go 355/25 the overall diameter is 0.7” shorter. Which mean you’ll lower the rear ride height by about 9mm, also increase the fender gap by 9mm.
Yeah, Porsche does weird things with the size on the back of the GT3 also. The stock size is a 305/30/20, but no tire in that size (aside from the OEM Cup2 and Dunlop) are safe to put on a 12" rim. The OEM 305 is as wide as all other 325's, but the sidewall height is like a 305/30, so you can't just go with a 325 without changing gearing, ride height, etc.
I think Porsche does this to provide an "Exclusive" to the OEM tire manufacturers, but by fibbing on the size, they are creating an annoying and potentially dangerous issue. I didn't realize the RS had the same issue...
Compiled a list of 21" rear tires for the RS. The 325's have the correct side wall height but various tread width between models.
The 355 PS4S has shorter side wall and might be too wide for a 12.5" wide wheel.
Also note that the Dunlops is the only 325 tire listed for 12.5 rim width.
I ordered a set of Michelin Pilot Sport 4S in RS size (265/35/20, 325/30/21) and in N spec. I plan on use these on the street or when the track gets too wet. I use a set of Forgelines with Dunlops for dry track duties.
Tires arrived Monday, and the fronts are a smidge wider than stock Cup2, but the rear is more than 20mm narrower ! Tire Rack listed the 325/30-21 tread width 11.5" for the PS4S and 12.8" for the Cup2.
Front: Cup2 vs PS4S
Rear Cup2 vs PS4S
How were you able to get the rear 4S in N spec for the RS? They’ve been on back order forever and still show back ordered on tire rack.
How were you able to get the rear 4S in N spec for the RS? They’ve been on back order forever and still show back ordered on tire rack.
My contact at Discount Tires said there were 3 in the entire country, Michelin wouldn't release them unless to a Porsche dealership. He had Discount Tire's head office involved to get two for me.
Sold me for cheaper than Tire Rack too !
I started with PS4S 325s and they were much too narrow/stretched compared to the PSC2s. Went to 355s and life is good. Yes, they cost 2x for no good reason, but they also fit properly.