Tire speed rating

[streetracer]

Symbol MPH Q 99MPH R 106MPH S 112MPH T 118MPH U 124MPH

H 130MPH V 149MPH

Z 149+ MPH

W 168MPH

Y 186MPH

ZR 149MPH I hope this helps anyone. And I did search before I put this in here.
Modified by streetracer at 1:07 PM 7/23/2005

[SmithSR]

Well done.We have a dedicated Tire/Wheel/Suspension forum to house all related info!

I'll move this info there and Chet will add / edit to his info pages.

[0wn3r]

Now here's a question. What do the letters actually mean? Also, why don't they actually go in order?

I didn't find the answer yet, but while searching I found this:

Speed RatingThe speed rating denotes the speed at which a tire is designed to be driven for extended periods of time. The ratings range from 99 miles per hour (mph) to 186 mph.http://www.safercars.gov/Tires...h.htm

anyone reading that right?

[Q45tech]

Unfortunately the speed ratings only apply to near new tires under 8,000 miles and under very rigid in door lab conditions [cool] GOING PERFECTLY STRAIGHT no curves!

Always chose a higher rating than you ever ever ever expect to go especially if you don't replace tires every 8,000 miles.

Always inflate tires to 35 psi cold if you expect to get within 80% of max speed rating.............for example an S tire rated at 112 mph should have 35 psi if you ever hit 89 mph.

On 51 psi max rated tires this gets bumped up to 40 PSI COLD!

LOWERING SPRINGS or just excess negative camber focuses the heat on the inner edge of tire this requires ADDED SAFETY FACTORS BE APPLIED TO TIRES!!!!!!!!!!!!!!!!!!!!!!!!!!!