[TomT]

Mind you I've never driven a Sport but an article in a local paper several months ago (which sold me on the RAV4) claimed the Limited had a smoother ride then the Sport. I don't know if the difference is that noticeable and it was not the deciding factor for me so much as what options I could get with the Limited vs the Sport.

 

[TomT]

The treadwear grade is a comparative rating based on the wear of a tire when tested carefully under controlled conditions. For example, a tire graded 400 should have its useful tread last twice as long as a tire graded 200. Another tire manufacturer, however, may grade a comparable design 300, so a grade of 150 would last half as long under their grading scheme. The lesson learned is to not use one manufacturer's grade versus the other, but instead to compare tire grades within a given brand.

http://www.discounttiredirect.com/d...foTreadwear.jsp;jsessionid=GD3vW8q24q5HR1kwlGBhSyStJJsnJfNtwyjpy4ZLW7p6n4G24zJQ

 

[TomT]

Seems to say the same thing.
From your link:

Typically, comparing the Treadwear Grades of tire lines within a single brand is somewhat helpful, while attempting to compare the grades between different brands is not as helpful.