@CapriRacer quote “Second, it is possible to have offsetting conditions. For example, an underinflated tire (which causes shoulder wear) mounted on a drive tire (which causes center wear) and that results in even but rapid wear.”
Good point. Adding weight to the back for the trip but not increasing the tire pressure to compensate would create this condition for the trip only.
A single alignment issue would cause uneven tire wear, but offsetting alignment issues could cause rapid but even tire wear. You would expect that all the time but negative camber caused by weight/weak springs/strut and toe in caused by push against worn bearings if the power is biased to the rear tires in the awd setup.
^
Of course, CapriRacer is correct.
While it is not unusual for OEM tires to have a very low treadwear rating, these were apparently selected by the OP as replacement tires, and I would say that they were not a good choice, based on that very low treadwear rating. Perhaps they have other redeeming qualities, but good treadwear was not designed into those tires in the first place.
Just to give the OP some perspective, most replacement tires are rated in the area of “500”, if not more, when it comes to treadwear. I wouldn’t buy a tire with a treadwear rating of less then 500, and my current tires–Michelin Defenders–have a treadwear rating of 820.
@CapriRacer Can You Talk About Why Wear Ratings Are Supposed To Be Used To Compare/Contrast Differences Among Tires Within One Brand And Not So Much Across Brands? CSA
Common Sense Answer asks: " Can You Talk About Why Wear Ratings Are Supposed To Be Used To Compare/Contrast Differences Among Tires Within One Brand And Not So Much Across Brands? "
Yes, we can and that’s another one of those tire myths perpetuated by folks who don’t understand about how this works.
First, there is a series of tests that are supposed to be run to get all of the UTQG ratings. The treadwear rating test consists of a route in Texas by a pair of vehicles (or more), that have a set of the SRTT (Standard Reference Test Tire) and the target tire(s). The SRTT (if I remember correctly) is a Uniroyal from years past, but specially built to insure consistency from batch to batch.
The test is something like 10K miles - and at the end of that, the wear rates are calculated which results in a value for the target tire.
This test has a lot of variability, so repeated testings will get different answers - something along the lines of 10%.
Then there is the problem that the SRTT only comes in one size, and sometimes you can’t fit that size onto the vehicles that fit the target tire - so the test procedure allows for testing against a known, previously tested make and model. So if one wanted to cheat the test, one would chose a tire that tested poorly previously and compare that to a test where the target did well.
PLUS -
The regulations only require the tire manufacturer not to OVERSTATE the ratings. In theory, this keeps everyone honest, but in reality, it allows tire manufacturers to adjust values downward for marketing purposes - like rating a midrange quality tire down a bit to make the premium tire look better.
So the truth is that there is a method that OUGHT to produce comparable values, but you have to take those values with a grain of salt (or the whole shaker). Yes! You can be sure a tire rated at 300 is different than a tire rated 600 (regardless of the tire manufacturer), but the difference between a 600 and a 650 isn’t as clear. And I think this applies both within a brand (or manufacturer) and between brands (or manufacturers).
The criticism of the UTQG treadwear rating is that it doesn’t produce real world results - that people don’t usually don’t get the mileage stated.
First, the rating is a comparison, not a mileage statement. A 600 tire is supposed to last twice a long as a 300 tire. Many people try to equate the rating to 300 = 30K miles - and below I’ll show you that just doesn’t work.
However, tire dealers have insisted that tires have some sort of mileage warranty so they have some way to compare and contrast. If you do a comparison of the warranties vs the UTQG treadwear rating, you’ll see a loose correlation. But treadwear warranties also do not work in a straightforward manner.
That’s because most tire wear occurs in the cornering mode. In order to generate the force necessary to move 2 tons of vehicle in a different direction, the tires have to produce a slip angle - the difference between the direction the tire is pointed and the direction it is actually going. And that scrubs off rubber - the more severe the cornering, the more rubber is scrubbed off. When doing severe handling maneuvers, tires last 10’s of miles.
On the other hand, a tire that goes straight ahead, is close to no wear at all! I’ve conducted tests where the range of mileage received was a 10 fold difference - 10K to 100K - and the differences were the road surface (new abrasive concrete vs well worn asphalt) and the service (local delivery vs hauls between cities.)
So it shouldn’t a surprise to see folks complain about not getting the mileage stated in the warranty. Only a small percentage of people are going to.
Does this mean the tire manufacturers are committing fraud? No, because a warranty is just a statement about what they will do IF the tire doesn’t reach a certain mileage, not a statement that every tire WILL reach it. There are no regulations about what a tire manufacturer can claim for wear, but the reality is that none of the warranty numbers are calculated much different between brands.