2015: grassroots likes the re71r and bfg rival s.
http://classicmotorsports.com/media/files/podcast/audio/grm_podcast_tiretest.mp3 Good general discussion, but does not cover true r comps.
2014: extreme performance summer:
http://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=197
2010 r comp comparo. R888 and sport cup here.
http://m.caranddriver.com/features/track-tire-test-bfgoodrich-toyo-michelin-and-yokohama-tires-rated-feature
Trying to find the article:
Grassroots Motorsports does comparison tests with DOT racing tires on an autox course. The Kumho Ecsta V710 is king, followed by the Hoosier A6, BFG R1, Nitto NT01, Hankook Ventus Z214, Hoosier R6 and Toyo R888. They haven't tested the Yokohama A048, Kumho Ecsta V700 or Kumho V70 Victoracer, at least not lately. I don't think they ever tested the Michelin PSC, but autoxers don't like them. A German magazine compared the Kumho Ecsta V700, Michelin PSC and Pirelli P-Zero Corsa. They declared the Kumho the winner. If you don't mind having a tire that has just two grooves and want the absolute grippiest DOT tire, get the Kumho Ecsta V710. If you want a tire with more grooves that can be used in the rain, it gets more complicated. The grippiest is probably the Kumho Ecsta V700, but they'll lose their grip before they wear out. The Toyo R888 will deliver more consistent grip over a longer period and over a wider temperature range. I plan to buy a set in the spring. That's what's in my avatar. The Nitto NT01 is basically the same tire with less grooves, but more than just the two grooves that most of the others have.
NASA's view on things:
A. TIRES:
1) The following DOT-approved R-compound tires: BFG R1S, Goodyear Eagle RS AC (auto- cross), Hoosier A7, Hankook Z214 (C90 & C91 compounds only), Hoosier Wet DOT (if used in dry conditions—see section 5.6) +22
2) The following DOT-approved R-compound tires: Hoosier A6 +17
3) The following DOT-approved R-compound tires and those with a UTQG treadwear rating of
40 or less not listed otherwise in these rules: BFG R1, Goodyear Eagle RS, Hankook Z214
(C71, C70, C51, C50), Hoosier R7, Kumho V710 +10
4) The following DOT-approved R-compound tires: Hoosier SM7 +9
5) The following DOT-approved R-compound tires: Hoosier R6, Hoosier SM6 (note:
Continental Tire Sportscar Challenge EC-Dry tires (225, 245, 275) OK) +8
6) The following DOT-approved R-compound tires: Toyo Proxes RR, Hankook TD +7
7) The following DOT-approved R-compound tires and those with a UTQG treadwear rating
over 40: Maxxis RC-1 (examples: Kumho V700, Michelin Pilot Sport Cup & MPS Cup 2,
Nitto NT01, Pirelli PZero Corsa, Toyo R888, Toyo RA-1, Yokahama A048, etc.) +6
8) DOT-approved (non-R-compound) tires with a UTQG treadwear rating of 120-200
(examples: BFG g-Force Rival, Toyo R1R, Dunlop Direzza Sport Z1 Star Spec, Bridgestone Potenza RE070, Kumho Ecsta XS, Yokohama Advan A046 & Neova AD08, Hankook R-S3) +2
9) Non-DOT-approved racing slicks +30 (of any origin--re-caps and re-treads are not permitted)
R comps: 2012. P zero trofeo R wins, R888 last.
http://www.tyrereviews.co.uk/Article/2012-Sport-Auto-Track-Day-Tyre-Test.htm