When getting new tires and a seller refers to a tire with a 60,000 mileage life does that mean that the actual tire is expected to reach a full wear pattern by a certain thickness or is that from a tested failure rate around that mileage? Though, Ive never been able to actually get the full mileage life of a tire even rotating and balancing during the suggestive intervals I've always wondered what the milage life meant when considering new tires.
When shopping for tires, some of them will have a mileage warranty, normally in the range of 40,000-70,000 miles. When a mileage number is listed, it is a pro-rated tread life warranty. When the tires are kept properly inflated, and rotated on a strict, verifiable schedule, they should give you the listed number of miles before the tread reaches the minimum safe tread depth (typically 2/32".. Which of course is 1/16", but everyone insists on calling it 2/32" for some unknown reason).
Typical tire mileage warranty advertisement
If the tires fail to last that long, and you can verify the rotations, and the tread wear pattern doesn't show any problems with inflation or alignment, then you will be entitled to a warranty claim based on the difference between miles traveled and the miles promised. As you can imagine, meeting all the requirements is a challenge, and in the end you're probably only going to get maybe 20% of the purchase price of only the tires, so most people don't bother unless the tires really under-performed.
Sport or specialty tires rarely have a mileage rating, but all tires should have a Uniform Tire Quality Grading (UTQG) rating (in the US). This value is a non-milage based number that ranges in the typical range of 400s-700s. This is a good number to keep an eye on rather than miles because it attempts to be standardized across brands. A manufacturer can put whatever mileage warranty they want, but the UTQG must be tested.
UTQG stamp on sidewall of a tire
I would assume it's a calculated estimate, based on an "average" wear rate for the compound used - I'd expect that they would run the tyre in controlled conditions for a certain mileage, measure the wear, and extrapolate out to give a full wear life.
As with all these things, the controlled conditions of the test means it's unlikely that many people would achieve it in real life...
About 4 years ago, I bought a set of General Altimax RTs for my 2007 Camry. On a dangerous driving scale of 10=highest, I'd say I drive around a 7. Almost always 10-15MPH over the speed limit on freeway and aggressive starts. My Camry has a V6 which has more than enough power to spin the wheels if I try hard enough. With this said, 4 years later, those Generals have gotten a lot louder, but their tread (UTQG ~700) is hovering at about 5/32 which puts them at about 50% used up. Over 50K on the set with rotations about once every two years and a lifetime alignment check every year, these tires have far exceeded what I was expecting from a General Tire. The downside is they don't like it when it's raining out. Rain traction is nearly non-existent- have to granny throttle it. But on dry days - look out! 50K miles and likely will get 70K before finally going after another set - probably the newer RT43!