June 2014 installed a set of Defenders from Costco. For the first 50K I let Costco balance & rotate the tires every 7.5 - 10K. Since then I have done my own tire rotations trying to get the best life out of the tires. The last 24K or so none of the tires has been balanced, but they still are fine. Somewhere in the first 50K I had two different tires develop a leak which Costco repaired at no charge. Tires have all been set to 44psi cold since new. I had been running the old tires at 44psi & they were doing good. Here is the tread depth as measured in mm across the tires. Top line is the front axle - Second line is the rear axle. The outside numbers are the outside of the tires - then center numbers are the inside measurements. 2.8 3.4 3.4 2.5 - 2.1 3.1 3.1 2.1 2.3 2.6 2.6 1.9 - 1.9 3.1 3.1 2.2 Ill probable make it to 80K before I get another set of Defenders. When I had these installed I never got an alignment - the previous tires were wearing so perfectly I did not want anyone to mess up the existing alignment. Unless something major happens I'm not getting an alignment when I do get new tires. Prius is at 193K & doing fine
that's fabulous, congrats! my oem's look great at 46k, but i'm getting a whumping sound from one of them.
Did the math, with 2.5 mm (rough average of your measurements), it translates to 3/32", getting pretty low. Sedate driving in good weather they're fine I'm sure, but I would swap them asap.