1: Have you looked at pictures of the SC2 ZP and new SC2 R? They look almost identical;

2: Reports from the Euro owners of GT3 RS’s is that they’ve talked to Michelin engineers about the ‘R’.

Yup, like I said above:

They do look almost identical, but with the SC2 R having noticeably deeper tread grooves and siping.

In talking to two GT3 guys a couple of weekends ago, I got the impression Porsche and/or Michelin must have provided owners with quite a bit of promo/technical info on the tires. I simply made a comment about the tire tread looking deeper than mine, and got a rather lengthy and in-depth response.