tread rating
 

whats the differnce between them all.

im looking at what tiures to get for my next set of rims. the tires im looking at are either H V or Z rated. but not all are the same tire. so which is better to have? for DD and SCCA?

The letter ratings are speed ratings and indicate the maximum manufacturer's recommended speed given proper load, stability, etc. It goes like this (starting with S since most decent tires for AutoX wouldn't be lower than S):

S = 112mph
T = 118mph
U = 124mph
H = 130mph
V (and Z) = 149mph
W = 168mph
Y = 186mph

But for SCCA you should be more concerned about treadwear ratings. The lower the rating, the stickier the tire and the better it'll handle. The trade-off is that it won't last as long. For instance, the Bridgestone Potenza RE050 has a super low rating of 140AA. Super sticky...short life. By comparison, Bridgestone's all season no-frills passenger car tire has a rating of 700AB. Those'll last forever but'll be hard as a rock. I prefer something like a Kuhmo Ecsta 712. The treadwear ratings are between 280-360 (depending on size and aspect ratio) so they're good enough for a daily driver, too.

thanks GT i was looking at getting the toyo T1S. theres thier rating:

V, W, Y and Z speed-rated (depending on size)
- UTQG Treadwear 280
- UTQG Traction AA
- UTQG Temperature A

would you recommend them for a DD and scca car?

On the whole I guess I would. A UTQG of 280 is a *little* lower than I prefer, but not by much. I like running at least a UTQG of 300-320AA at least. You could always go with a dedicated set of AutoX tires like the Nitto NT555R II Extremes. I did a few laps on a borrowed set of those things and felt like I was glued to the track. Then again....they carry a UTQG of 100. What size wheels are you running? That'll be the biggest factor in what tires will work best.

im looking at using my stock rims as DD and the Rotas as Auto. theyll either be 17 or 15.

For AutoX I'd go with either Yokohama AVS Sports or Falken Azenis Sports. For the stock rims I'd go with something like a Yokohama A032R. Those things own...just not for too long.

im likin my kuhmo all seaon tires. that are on my DD rims right now.

but i plan on getting a set of DD and SCCA rims for the summer time. i think the T1S ill work for what im going to be doing.

Look at the Kuhmo V700s for racing, nice cheap tire.

Here's some info on Street legal race tires.
http://www.club4ag.com/faq%20and%20t...0Selection.htm