Replaced all tires (22.5) at a cost of $1800 when we bought the MH,
Why, because although they looked ok, they were 7 years old and we had no idea how they were treated.
When we replaced the tires we put Toyo's on and the handling is very good. However the question of how often should you replace your tire s comes down to a few simple questions.
1. How often do you drive the MH per month? If it is rarely then the tires tend to diminish with being square wheeled creating flat spots. Sun will also cause the rubber to crack which is a potential blow out wait down the road.
2. Tire preasure is very important, its surprising how many RV's never check their tires ! You can also add Alignment and balancing to the list, of which both should be checked anually. And visually inspections prior to making a trip is important.
3. Tire Size makes a difference to how the tires will wear, My old MH had a 19.5 tire, and with all the ruts in the road trying to go straight was sometimes a challenge, the uneveness of the road also tends to cause extra wear.
My present tire size is 22.5, road holding is 100 % better and there is no wondering or problems with passing trucks.
4. Now as to how often you should change them is really a personal preference, I read from many that an inspection is advised. Thats fine so long as the inspector isn't selling the tires ! Otherwise 6 years is the new recommendation, and 6 years is now recommended for the toad and private vehicle.
Tires are mde in China Indi and other locations around the world, the Major names also have equally cheaper tires of the same quality as the expensive known brands.
And keeping your eyes open will also show MH's that get flats are generally running on old tires that are neglected, after all the Ad is right, you have a lot riding on your tires,
Keep the shiny side up...