frayed:

Turbo wheels are being used to run narrower snow tires.

The Winter CL wheels for the Turbo/TurboS are also narrower (at least according to Porsche): 8.5x20F & 11x20R winter vs. 9x20F & 11.5x20R standard, although only the rear tire is narrower (295/30 winter vs. 305/30 standard) while the front is 245/35 on both.