[Freon]

The "hot" tires this year for autocross seem to be the Rivals or Z2s. They're likely the best performing tire you can get for street legal tires besides some of the borderline R-comps like R888, etc. Rather, 140TW or greater which I think is the current SCCA Solo cutover for what is considered a "street" tire. The PSS is a much higher treadwear, and as much as I think Michelon knows how to build tires I think they're not going to match the grip of a Rival, Z2, RE-11, or RS3 and miraculously last 50-80% longer at 5-15% less price.

I have slightly more faith in the Z2 in the wet vs. the Rival due to the tread pattern. The Rival has no aqua channels. The Z1 was actually damn good in the wet when new. I did extremely well with Z1s in a local autocross (Winged Warrior in 2011) in sopping wet conditions, huge puddles, etc. even beating out a ton of AWD cars in the next class above mine. It does appear the Z2 has slightly less channeling, but it still way better than a Rival.

I would recommend the Z2 for most people wanting a great performance tire with minimal concern over treadlife. The Z1 was pretty darn good in dry and wet conditions, and certainly perfectly safe on the street. PSS might be a good choice for those slightly more treadwear/life sensitive, and that's why I went with the PSS this time.

Fair warning on the PSS, the 275/35/18 seems to have LESS actual tread than the 255/35/18 due to HUGE bands of void in the middle.