A pneumatic or air-filled tire consists of an inner core which is sealed airtight and filled with pressurized air. Usually, a reinforced steel belted tread or other materials, provides the contact part with the road and seals this inner core.
The tire will remain inflated with all the weight of the vehicle resting on it, as the pressure of the air within the tire is more than atmospheric air pressure. The pressure of the air within the tire provides resistance against forces which attempt to deform the tire. When the tire hits bumps in the road, this gives the tire a slight degree of a cushioning effect. If you have experienced taking a ride in an old-fashioned carriage which had wooden wheels, you know how huge of a difference a set of pneumatic tires makes.
Of course, there are several disadvantages to pneumatic tires. For example in high-performance situations or highly dangerous applications, these tires can suffer a puncture and this will lead to a total failure. The consequence of a blowout at high speeds can result in a dangerous car crash. Military planners should take into consideration tires getting blown out by explosion shrapnel or gunfire. The worst nightmare of a vehicle crew is becoming trapped in a fire zone because of all of their tires becoming flat. Airless tires obviously don't suffer from these type of issues and therefore, in some applications, may be more suitable.
The pneumatic tire might have issues as well with the variation in air pressure and tire performance. The lower pressure in a tire may increase the comfort level and the traction. This is due to the fact that tires flatten a little and more tread is placed in contact with the road. The air pressure inside of the tire works to maintain the "up and down" stiffness as well as maintain the lateral stiffness of the tire. Thus, reduced air pressure enables the sidewalls of the tires to flex. Unfortunately, this results in poor handling. In an airless tire, the stiffness in those two dimensions is independent.
Air pressure factors into other issues too. When it comes to maintaining correct air pressure, customers are notoriously unreliable. Wrong air pressure within tires can result in very dangerous situations. It is very important to note that pneumatic tires are also prone to temperature changes, which can be responsible for changing the internal pressure of the tire. It is vital to take into consideration the kind of settings you will be needing your machine to operate in so that you could frequently inspect the tires and keep the machine as safe as possible.