I would tend to be more like Ron than some of the other views expressed. Maybe some of you really put the miles on your units, but most of us will take a long time to really wear out their tires. I've got a 6 year old unit that I bought 2 years ago with 4K miles on it. The first owner stored it indoors and the tires looked like new then. I store it inside and the tires still look like brand new with 15K on the unit. How long will a tire last? If you look on Google, you will find that some sources recommend replacing when the tire is 5 years old. I suspect that these sources are somehow involved in selling tires. Most manufacturers seem to recommend replacing the tires at 10 years regardless of how they look. If you keep your unit out of the sun and harsh weather, you should not have a lot of trouble with cracking between the tread ridges or crazing of the sidewalls in 10 years with quality tires. I have always used Michelins on most of my vehicles and have gotten great life out of them. IF you could find a good shop for aligning large chassis vehicles like RV's, I suspect that would be more effective in cutting tire wear than rotation would be. The exact rotation pattern is not as clearcut for dual rear wheels as it is for the normal car. Also, if your vehicle is well aligned, rotation should not be that critical. As far as balancing is concerned, your steering wheel and your ride will tell you if you have a problem there. Remember that current methods of balancing wheels are not as effective as they once were because safety concerns preclude spinning them on the vehicle at highway speeds, which is the only way to get a perfect balance. I tend to check my tires for wear that might indicate alignment problems, balance the front wheels when I feel any vibration in the steering wheel, and will consider replacing the tires when I see excess wear, sidewall crazing indicating dry rot, or splits between the treads. I would also probably change them at 10-12 Kmiles if I ever keep one that long.
