Ah …. Mmmmmm …… not exactly.
The variability is inherent in the test. All the tests are conducted on the same public roads in Texas using a convoy of vehicles. While a tire manufacturer can use its own vehicles and drivers, it is more common for manufacturers to hire an independent lab who runs many tests at the same time, thereby reducing the cost.
The real problem is that the test is only 10,000 miles long and small differences in measurements result in fairly large differences in results. And that doesn’t take into account that weather is an uncontrolled variable. The manufacturer I worked for (and I assume all the others as well) have a lot of data where the same tire is run repeatedly over the course and the variability is obvious.
For example, each test is supposed to be run against the SRTT (Standard Reference Test Tire), a Uniroyal tire specially made by Michelin with certified materials and carefully followed in the manufacturing process and stored in a controlled environment until use. There is a lot of data on this tire over the UTQG course. Unfortunately the SRTT is an old size and only fits on certain cars, so it is permissible to use another tire as a reference - something more modern and more compatible with available vehicles (SUV’s for example.)
I’ve estimated that tires rated with 10% of each other are essentially the same. Outside that 10%, then those differences are likely real. One of the other problems is that pavement surfaces can drastically affect what a consumer experiences. for example, southern Florida uses “new” limestone and the sea shells can still be seen. Those sharp edges easily cut the rubber when the pavement is new, and it takes a while until the pavement wears off those edges.
Not to mention that most tire wear occurs in cornering, so driving in a straight line is almost free miles.
As a result, consumers can experience widely different wear rates on the same tire. My field testing has seen as little as 10K miles and at much as 100K miles from the same tire. Your mileage may vary!!