I examined a Toyo Proxes RA-1 competition tire and a Hoosier competition tire the other day and I am puzzled. On the tire sidewall the RA-1 had a traction rating of "AA" and the Hoosier had a traction rating of "C". Since both are labled and sold as competition tires and both are fairly well regarded as being good racing tires, why is there this difference in the traction rating?

Aren't traction ratings manufacturer-specific? Wear ratings are standardized on road tires, but traction ratings are assigned by the manufacturer and by the individual model. At least I think thats how it works. I.e. two manufacturers might consider the same "type" of tire two different ratings, so a "AA" tire for one company might only be a "C" for another that has several, more sticky compounds in the lineup too. I'm not positive, so don't shoot me if I'm wrong.

The traction rating is based on all weather conditions. If you took a set of Hoosier R6s out in the rain you'd be screwed since they are a DOT approved slick while the toyos have decent tread. It has nothing to do with tread compound or softness. The treadwear numbers tell how soft the rubber is more or less. The Hoosiers have a treadwear of 40 which is softer than the RA1s 100 rating.

Yep, lower treadwear numbers generally means more grip in the corners.

http://www.tirerack.com/tires/tiretech/tec...e.jsp?techid=48

Thanks for setting me straight guys. I had often assumed that treadwear must still be somehow linked to grip (obviously softer usually means stickier), but didn't know quite how the traction rating factored in. Thanks

Thank you one and all for your responses. I now have a much better understanding of tire ratings and general traction/treadwear/rubber compound concepts.