Yep, I ran my RE71s on the street and track (15-18 autocrosses), as well as some fun mountain runs.
I've had a little bit of time to test out the Kumho 712s and compare with the old RE71s. The Kumhos still need some time to break in though, so what I can offer is only initial impressions.
They seem to be pretty sticky. I tried a couple highly aggressive maneuvers - a braking test and a test of full throttle acceleration around a turn with a rapid gearchange in the middle - and heard nary a peep from them. The downside, at least for now, is that steering feel is pretty poor. This could be due to my new wheels or the fact that the Kumhos actually have tread, though.
Braking feel is also lacking, and more pedal effort is required, though stops are still very short.
My early impression is that the Kumhos have overall grip levels comparable to the RE71s, but the RE71s felt so much better in terms of telegraphing their proximity to their limits while filtering out jarring road bumps.
Note that the MKI MR2 has some of the best, most direct steering in a modern car. I doubt those of you with power steering would be able to feel such a difference.
No verdict on the Kumhos just yet. I've been told they will get better, dynamically, with age. And perhaps it's not fair to compare bald RE71s with full-tread Kumhos.
Just some food for thought.
And check out my [url="http://www.mr2pages.com/members/bryanh/pics/newrims/"]spiffy new rims[/URL]!
[13lbs in 15x6.5, and cheaper than K1s to boot]
[i][url="http://move.to/theMR2"]1987 Toyota MR2, C-Stock[/URL][/i]
[This message has been edited by BryanH (edited January 26, 2001).]