Hi - moving into my third season of HPDE, mostly PCA blue hopefully white by end of season. Car is 2018 718 Cayman S, upgraded pads and rotors and front Tarrett camber plates, camber -2.0 all 4 wheels. Otherwise stock. I've done my first two seasons on the OEM 20" wheels and 400 TW tires. I'm ready for something grippier and just bought a set of Apex SM-10 wheels :

F 18 x 9 offset 46
R 18 x 10.5 offset 44

as recommended on their excellent fitment guide.

The guide suggests a couple of tire size options that will work. I'm between the following:


F 245/40/18 R 275/40/18

or

F 255/35/18 R 275/35/18


The car will be driven to and from the track on these tires; I'll be using 200 TW tires (RE 71 RS or similar).
What are the pros and cons of these two size options? Mostly interested in performance aspects; I know the 40's are generally a little cheaper.
Any differences WRT ABS/PTV, etc.?

Thanks in advance for thoughts.

 

For primarily track use the Front 255/35/18 and Rear 275/35/18 should be the better performing option. Wider front tire will increase front grip reducing understeer leading to a more neutral balance and the shorter sidewalls should feel more responsive to inputs.

The 255 F and 275 R option is off the factory front to rear tire height deviation by 1.2%, which is well within tolerance for the vehicle's assist systems (ABS, TCS, etc).

- Brandon

 

Excellent, thanks - ordered some RE71RS in that fitment. Really appreciate your participation in the forums as well as the fitment guide on your website. Not to mention the beautiful wheels and great service!