OTR tires are under much more stress than the ones that you use to take the kids to school. They have to bear up under enormous loads and roll through conditions that would puncture a standard tire. The most important factor of proper maintenance is to have it inflated to the correct pressure as recommended by the manufacturer.
An under inflated OTR tire has too much deflection which will cause too much flexing in the sidewall. When a tire is in continuous use with excessive deflection it will cause:
The tread to wear out unevenly leading to a drastic reduction in the life span
The sidewalls to begin to crack under the irregular flexing of the material
The steel cords that provide strength for the tire to begin to loosen or break
The ply of the tire to begin to separate
The fabric of the tire will begin to deteriorate and fatigue as well as the belt edge to separate
It is important to read the inflation recommendation for the specific tire instead of assuming that they are all the same. An OTR tire that is rated for soft ground does not need to be inflated as much as one rated for the pavement. That is because when the tire rolls through soft ground the it will make an impression. The impression in the dirt provides extra support for the off the road tire. Since the deflection of the tire is reduced the tire pressure can also be reduced. The tires that run on hard surfaces do not have the added support; they have to reduce deflection by running with a higher pressure.
Many construction workers and other contractors that use OTR tires prefer to operate them while under inflated because it gives a few benefits:
The tires are more resistant to puncture, cutting and impacts which is helpful considering the debris at most construction sites
The tires offer better traction and better flotation for operation in marshy areas
A note to remember about OTR tire inflation is that it will change during operation of the machine. While the tire is spinning it is building up heat which heats the air inside the tire causing it to expand. The tire’s carcass prevents the gas from expanding so the pressure inside the tire goes up. Do not ever bleed off the air in a tire after it has been in use because once it cools it may become dangerously under inflated.