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Problem is that the 200TW is not a standard in of itself.



All the 200tw rule will drive is turning 100tw tires into 200s to meet the rule.

I mentioned it in the 295 tire thread, but tread wear ratings are not absolutes. Instead they are a relative ratings within that specific manufacturers line of tires.

Mickey Thompson makes a lot of very specialized, high grip racing tires. If a race slick is rated 0, then a tire that lasts twice as long is 100 and one that last four times as long is 200. However, at the four times longer tread life, they are only claiming 15,000 mile capability on a street car, I'd say that tire is fairly soft.

By contrast, Multi-Mile makes tires regularly rated at 400tw ratings that go 50-60,000 miles. To cut that mileage in half and get a 200tw rating, they change the formula and give up 30,000 miles, but you have a tire that is still twice as hard as the MT example above.

Even the recent Hot Rod tire test showed that not all 200 rated tires are equal in grip. If the 200tw rating was an absolute, then it would have produced results a whole lot narrower.

Maybe the key is to call out a durometer rating instead. This prevents anyone from soaking their 200tw tires in compounds to turn them into 40s.