Saw this while perusing the ChumpCar forums:
Tire Rack's official update regarding the subject:
Hankook Tire has changed the Uniform Tire Quality Grade (UTQG) Treadwear rating of their Ventus R-S3 Z222 Extreme Performance Summer tire.
UTQG ratings for Treadwear, Traction and Temperature are based on tests conducted by tire manufacturers and reported to the NationalHighway Traffic Safety Administration (NHTSA). These regulations allow tiremanufacturers to under-rate their tires’ capabilities, but prohibit over-rating them. UTQG ratings are required to be branded on each tire’s sidewall and printed on the tire label.
When the Ventus R-S3 Z222 was introduced in spring of 2009, Hankook assigned 140 Treadwear rating to match the UTQG Treadwear rating required by car club competition rules. However subsequent Hankook wear data revealed the tire line provided equivalent wear to its predecessor (Ventus R-S2) and earned the same 200 Treadwear rating. This is also supported by Tire Rack survey results and feedback from our customers indicate the Ventus R-S3 Z222 provides equivalent wear to other tires already featuring similar UTQG Treadwear ratings.
With changes in car club competition rules now requiring higher UTQG Treadwear ratings, Hankook decided it was time to change the rating to better reflect their tire’s capabilities.
Since 140- and 200-Treadwear rated tires are available, both appear on NHTSA’s safercar.gov website for the Ventus R-S3 Z222 line.
Since no changes were made to tire compound or construction, all Ventus R-S3 Z222 tire sizes continue to use the same Hankook S-Code (part number) and both 140- and 200-Treadwear-rated tires are compatible when put into service as singles, pairs or in any combination.
In order to help drivers confirm which tire they will receive, Tire Rack has separated the tires and listed the Treadwear rating on its product Specs tab. Changes to the website should appear tomorrow, April 5th.
Looks to me like just about all of the ST tires are going to 200TW as the line between street tire and competition-only tire. Discuss.