Why Your Tires' Treadwear Ratings Are A Load Of Crap

Illustration for article titled Why Your Tires' Treadwear Ratings Are A Load Of Crap

Between amateur endurance racing and the Sports Car Club Of America's "Street" autocross classes, there's quite a few series now mandating around 200-treadwear rubber. So, of course, different tire manufacturers are "readjusting" ratings of existing tires to cash in on the action.


Uniform Treadwear Quality Grades are what separate a tire from being legal for series such as the 24 Hours of LeMons (190-treadwear minimum) or not. Lower UTQG ratings generally wear faster, but are considerably stickier to compensate for that.

Sticky tires = more grip in turns = more speed you can carry through turns. Pretty simple, really.

Of course, violating rules on treadwear generally means anything from disqualification to public shaming (should you be at a LeMons race). One team who showed up on R-compound tires at the last LeMons race was forced to carry their cheatin' wheels all around the paddock to apologize to everyone else.

However, all of the tests for UTQG are done by the tire manufacturers themselves. Per Tire Rack:

UTQG ratings for Treadwear, Traction and Temperature are based on tests conducted by tire manufacturers and reported to the National Highway Traffic Safety Administration (NHTSA). These regulations allow tire manufacturers to under-rate their tires' capabilities, but prohibit over-rating them.

This, of course, is the magical loophole that tire manufacturers are taking advantage of lately.

The first tire to magically adjust its rating to appease the low-cost racing classes was the Hankook Ventus RS-3. It had debuted with a stickier compound than Hankook's previous RS-2, but with a 140 treadwear rating.


Hankook claimed that subsequent testing led them to believe that the RS-3 deserved a 200-treadwear rating just like its predecessor had, so nothing was changed on the tire itself besides the addition of a new UTQG stamp for "200" versus "140."

If this sounds as wishy-washy as you think it sounds, well, yes. The fact that tire manufacturers are allowed to under-rate a tire's treadwear rating makes the published ratings sort of a crapshoot. You can get a general idea of how fast a tire will wear out based on its published treadwear rating, but as far as which 140 vs. 200 treadwear tire you should use on your track toy goes, you're better off looking at published reviews or asking current owners for their opinions. Some tires in this range take the heat of being on a heavier car better than others, too, so be sure to look at opinions from users with similar cars to yours.


Right around when Hankook adjusted their rating on the RS-3, the Bridgestone Potenza RE-11 came out with 200-treadwear stamps.

And now, we have one more: the Toyo Proxes R1R. Like the RS-3 and RE-11, it's a reclassification of the same ol' 140 treadwear tire everyone already knows.


This reclassification also coincides with the fact that in 2015, 140-treadwear tires are no longer legal for use in the Street class for SCCA Solo autocrosses.


Previous tests have indicated that the R1R wears fast, overheats quickly and doesn't like abuse, but that it's a great autocross tire. "Bring a water sprayer and drive gently." advises Matthew G. Huizing of the Furrin Group.

Wear-wise, that sounds like a world apart from the Dunlop Direzza ZIIs that usually take about a year's worth of occasional but frequent track abuse on my 3,000-lb pig of a daily driver before finally giving up the ghost, yet both tires are rated as 200-treadwear.


Treadwear ratings are BS. The ability to under-rate them to convince track geeks they're sticky makes them more of a marketing ploy than an accurate form of measurement.

Either way, if you're doing shorter forms of entry-level racing, it looks like you've still got the option of the R1R next year.



This is no more fishy than tire mileage ratings. Show me a tire that actually goes 60000 miles and still has tread on it.