How many miles do you get out of your good tires?

If you make a lot of tight turns on paved surfaces then I could see how a triple axle trailer could go through tires fairly quickly. I know on my 5th wheel, anytime I make a turn the front axle and rear axle's tires "scrub" laterally on the pavement. I just replaced the factory China bombs and 4 of the 6 tires had some lateral wear. The middle tires were perfect.

Do you rotate your tires? If you don't, then doing so might get you about 5000 extra miles based on your estimate of mileage.