Originally posted by ACR_Motorsports:
the RE-040 is only Y-Speed rated versus the Z-Speed rating of the
RE-010s.
(from TireRack website)
http://www.tirerack.com/tires/tiretech/general/speed.htm
Z=149 MPH, 240km/h and over, Sports cars
W=168 MPH, 270km/h,and over, Exotic Sports cars
Y=186 MPH, 300km/h,and over, Exotic Sports cars
When Z-speed rated tires were first introduced, they were thought to reflect the highest speed rating that would ever be required. Since that time the automotive industry has found it necessary to add W- and Y-speed ratings (indicated in the tire’s service description) to identify the tires that meet the needs of new vehicles that have extremely high, top speed capabilities.
While all Z-speed rated tires are capable of speeds of 149 mph and above, prior to the W- and Y-speed ratings were identified in the service, how far above 149 mph was not identified.
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so Y > W
all Y and W are Z (>149 mph)
Z can be either W or Y
Z is potentially better than W, but at best equal to Y... AFAIK there are no road tires rated above 186 mph...
[This message has been edited by cojones (edited 11 September 2002).]