I posted a few months ago about the 15" tire combo that I am running that's a bit different from the standard Yoko's or BFG's. Nitto Drag radials 275/60 in the back and Pirelli P600 235/60 in front. Both are Z-rated, I found the Pirelli's on Tire Rack while looking for a good front tire to match the Nittos. [***Edit: The Pirellis are W-rated (168 mph) not Z (>149mph), I don't think the Z-rating is used as much anymore.***]
There was some discussion about whether the drag radials were suitable for the street (they are) and whether the Pirellis were any better than the BFG's or Yoko's (yep). I said I would post back on my impression of the Pirellis once I got a chance to put them to the test a bit and I was already a big fan of the Nittos. Well, I've been to a few autocrosses, drag strips and put about 1500 miles on them, and I have to say, this is a fantastic combination for all around performance. My confidence in the car has soared, it is much more predictable with a higher limit of adhesion.
As to whether the drag radials are good for anything other than the dragstip and whether the Pirellis perform, I offer this video as evidence:
http://www.youtube.com/watch?v=r3-x_6Tg6lQ
It's five runs of a night autocross. I ran the car set up exactly the way I drive it on the street, I only checked the tire pressure (24 rear, 26 front). My best was 47.4 secs. For comparison, the Miatas were running high 46's, 47's on the same course, but with the benefit of running while there was still daylight (one guy did turn in a magnificent 43 in a Miata, damn those things
).
There's a small surprise about halfway through, happened in my 3rd run
And the cheerleader you hear in the background is my 2yo daughter, she pops up in the video as well. She already loves to "watch the race cars"!
