In a nutshell.
If you have true 16" wheels, you can buy light truck tires in the right load rating. They will have a recommended replacement life of 5 years.
If you have 16.5" wheels, then you will probably only have one choice of tire (Firestone TransForce), but it will be a true motorhome rated tire with a life of 7 years.
Main thing is to understand how to read the load ratings of your tires, ensure you have the right ones and match whatever you have. Also understand how to read the manufacture date on the tire. You can look both up on the interwebz.
Jose