Tire Questions

[Nick H]

I rotated tires last week along with some routine maintenance and they are pretty much worn out. Wear seems pretty even, perhaps a bit more on the inside edges. But my issue is that these are original tires (Toyo Proxes R28 205/40R17) with only 15,000 miles! I keep 'em inflated properly; are these just crap tires?

Anyway, I need some new ones - any suggestions? It's a 2005 MSM that I drive mostly around town and country roads - no racing or autocross. Thanks!

[CosmosMpower]

90% of the people here would be more than happy to get 15,000 out of a set of tires, especially on a FI miata.

[Magma]

I don't think my stock tires lasted that long, just get used to buying tires once a year

[Nails]

Welcome to the forum.

Couldn't find that particular Toyo but the ones I did find had a tread wear rating of 300 or more except the T1R which was 280. The RA1 and R!R's were 100 tread wear but I think they're R compounds.

So does a tread wear rating of 100 bu UTQG mean 10k miles?

I found this on Tire Rack's site.

Unfortunately, the rating that is of the most interest to consumers is the one that appears to be the least consistent. While the Treadwear Grade was originally intended to be assigned purely scientifically, it has also become a marketing tool used by manufacturers to help position and promote their tires.
Treadwear Grades
UTQG Treadwear Grades are based on actual road use in which the test tire is run in a vehicle convoy along with standardized Course Monitoring Tires. The vehicle repeatedly runs a prescribed 400-mile test loop in West Texas for a total of 7,200 miles. The vehicle can have its alignment set, air pressure checked and tires rotated every 800 miles. The test tire's and the Monitoring Tire's wear are measured during and at the conclusion of the test. The tire manufacturers then assign a Treadwear Grade based on the observed wear rates. The Course Monitoring Tire is assigned a grade and the test tire receives a grade indicating its relative treadwear. A grade of 100 would indicate that the tire tread would last as long as the test tire, 200 would indicate the tread would last twice as long, 300 would indicate three times as long, etc.
The problem with UTQG Treadwear Grades is that they are open to some interpretation on the part of the tire manufacturer because they are assigned after the tire has only experienced a little treadwear as it runs the 7,200 miles. This means that the tire manufacturers need to extrapolate their raw wear data when they are assigning Treadwear Grades, and that their grades can to some extent reflect how conservative or optimistic their marketing department is. 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.



Hoped this helped some.

[CosmosMpower]

Welcome to the forum.

Couldn't find that particular Toyo but the ones I did find had a tread wear rating of 300 or more except the T1R which was 280. The RA1 and R!R's were 100 tread wear but I think they're R compounds.

So does a tread wear rating of 100 bu UTQG mean 10k miles?

I found this on Tire Rack's site.

Unfortunately, the rating that is of the most interest to consumers is the one that appears to be the least consistent. While the Treadwear Grade was originally intended to be assigned purely scientifically, it has also become a marketing tool used by manufacturers to help position and promote their tires.
Treadwear Grades
UTQG Treadwear Grades are based on actual road use in which the test tire is run in a vehicle convoy along with standardized Course Monitoring Tires. The vehicle repeatedly runs a prescribed 400-mile test loop in West Texas for a total of 7,200 miles. The vehicle can have its alignment set, air pressure checked and tires rotated every 800 miles. The test tire's and the Monitoring Tire's wear are measured during and at the conclusion of the test. The tire manufacturers then assign a Treadwear Grade based on the observed wear rates. The Course Monitoring Tire is assigned a grade and the test tire receives a grade indicating its relative treadwear. A grade of 100 would indicate that the tire tread would last as long as the test tire, 200 would indicate the tread would last twice as long, 300 would indicate three times as long, etc.
The problem with UTQG Treadwear Grades is that they are open to some interpretation on the part of the tire manufacturer because they are assigned after the tire has only experienced a little treadwear as it runs the 7,200 miles. This means that the tire manufacturers need to extrapolate their raw wear data when they are assigning Treadwear Grades, and that their grades can to some extent reflect how conservative or optimistic their marketing department is. 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.



Hoped this helped some.

RA1's are R compounds, but for road racing not autocross. R1R are not a R compound but rather a very soft street tire used for ST class racing. The treadwear numbers are approximate and vary by model and manufacturer. That is to say a 500 treadwear all season tire Goodyear would last exactly 5X longer than a 100 treadwear Toyo RA1 etc. Sometimes manufacturers raise the treadwear to make the tire seem like it will last longer and sometimes so it can play in a SCCA class etc.