The pneumatic tire or air-filled tire is composed of a core filled with airtight sealed pressurized air. Normally, a reinforced steel belted tread or other materials, seals this inner core and provides the contact area with the road.
Because the pressure of the air within the tire is greater than atmospheric air pressure, the tire remains inflated even with a vehicles' weight resting on it. The pressure of the air inside the tire provides resistance against forces that try 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 ever taken a ride in an old-fashioned carriage which had wooden wheels, you understand precisely how huge of a difference a set of pneumatic tires can make.
Of course, there are some drawbacks to pneumatic tires. Like for example in highly dangerous applications or high-performance situations, these tires could suffer a puncture and this would result in a total failure. The consequence of a blowout at high speeds can result in a dangerous car crash. Military planners must consider tires getting blown out by shooting of guns or explosion shrapnel. A vehicle crew's worst nightmare is becoming trapped in a fire zone because of all of their tires becoming flat. Airless tires evidently don't suffer from these kind of issues and therefore, can be more suitable in some applications.
Pneumatic tires have one more issue involving variations in tire performance and air pressure. Lower tire pressure can create increased comfort and improved traction. This is because of the fact that tires flatten a little and more tread is placed in contact with the road. The pressure of the air inside of the tire works to maintain the "up and down" stiffness as well as maintain the lateral stiffness of the tire. Therefore, reduced air pressure enables the sidewalls of the tires to flex. Unfortunately, this leads to poor handling. Within an airless tire, the stiffness in those two dimensions is independent.
There are other problems with air pressure. Consumers are notoriously unreliable when it comes to maintaining correct air pressure. Tires that have wrong air pressure could lead to dangerous situations. It is important to keep in mind that pneumatic tires are susceptible to temperature changes also, that could be responsible for changing the internal pressure of the tire. It is important to take into account the kind of environments you will be requiring your equipment to operate in so that you can regularly inspect the tires and keep the machinery as safe as possible.