GTS 4.0 Tire Fitment

[JP4931]

I had to replace my tires on my 21 CGTS at 6000 miles. I never liked how the 265's looked on the rear at all as they look stretched to me. I decided to order GT4 sizes 245/35/20 and 295/30/20 instead of what came on the car from the factory. I now have had these sizes on the car for 2000 miles with no issues of rubbing at all. I have one HPDE and three autocross events on them also. In my opinion these look much better. A word of advise, if you go with PS4S do not try and run the GT4 tire pressures on track. They will chunk the sides of the tire really bad. I forgot that the GT4 comes with Cup 2's. This cost me another set of fronts within 1700 miles.

[Tom]

I had to replace my tires on my 21 CGTS at 6000 miles. I never liked how the 265's looked on the rear at all as they look stretched to me. I decided to order GT4 sizes 245/35/20 and 295/30/20 instead of what came on the car from the factory. I now have had these sizes on the car for 2000 miles with no issues of rubbing at all. I have one HPDE and three autocross events on them also. In my opinion these look much better. A word of advise, if you go with PS4S do not try and run the GT4 tire pressures on track. They will chunk the sides of the tire really bad. I forgot that the GT4 comes with Cup 2's. This cost me another set of fronts within 1700 miles.

Did it throw off the speedometer at all?

[JP4931]

I had to replace my tires on my 21 CGTS at 6000 miles. I never liked how the 265's looked on the rear at all as they look stretched to me. I decided to order GT4 sizes 245/35/20 and 295/30/20 instead of what came on the car from the factory. I now have had these sizes on the car for 2000 miles with no issues of rubbing at all. I have one HPDE and three autocross events on them also. In my opinion these look much better. A word of advise, if you go with PS4S do not try and run the GT4 tire pressures on track. They will chunk the sides of the tire really bad. I forgot that the GT4 comes with Cup 2's. This cost me another set of fronts within 1700 miles.

Did it throw off the speedometer at all?

Honestly I have not even thought about checking that yet. I will check it Sunday on the way to a autocross and let you know.

[JP4931]

I had to replace my tires on my 21 CGTS at 6000 miles. I never liked how the 265's looked on the rear at all as they look stretched to me. I decided to order GT4 sizes 245/35/20 and 295/30/20 instead of what came on the car from the factory. I now have had these sizes on the car for 2000 miles with no issues of rubbing at all. I have one HPDE and three autocross events on them also. In my opinion these look much better. A word of advise, if you go with PS4S do not try and run the GT4 tire pressures on track. They will chunk the sides of the tire really bad. I forgot that the GT4 comes with Cup 2's. This cost me another set of fronts within 1700 miles.

Did it throw off the speedometer at all?

I almost forgot to check this on the way home from autocross today. I can only confirm that 60 mph and below are spot on with the waze app.

[Creampuff]

Considering the same swap for my 2022 BGTS 4.0
What pressures do you recommend for spirited street use?
Thanks

[WillyDaP]

Gentlemen, the PS4S is a great overall tire for an occasional autocross or track event , but please do try and get as much negative camber in the front as the factory will allow as they ( PS4Ss ) do have a tendency to take down the outside edge. You might try getting a set of 19s or even 18s for wider or simply stickier rubber , and you will observe most of the guys in SCCA Autocrosses are running 19s. You are allowed to drop down a size and stay legal if wanting to run in a Stock Class. If running a more prepared Class or depending if track time is your main desire, 18s will offer even more tire choices.

I am happily running on a set of Apex Forged 9x18s in front with 10.5x18s in the rear and the shifts through the PDK are lightning quick. With 255s up front and 295s in the rear the GTS stays up with much faster rides and I am sure the speedo might be off a bit, but it sure is fun. My second set of wheels is a similar set of Apex Flow Forged 19s ( 9s in front and 10.5s in back ) with some Bridgerock RE71RS shoes helping my little Chalk Croc Mistress dance with aplomb. Regardless of the tire you may choose, the car needs much more camber than the factory set, and in my estimation , much more than the limited factory maximum. For tire wear and to save those outside edges a Rennline or Tarett camber plate will help out quite a bit , and one may be necessary to install some wider sizes ( basically in the front ). I love Michelins for a great all around tire, but if you want to play and go fast there are some better choices imho.