A tire inflator is usually nothing more than an air compressor, though there are some designed specifically for inflating tires. While a simple hand pump can also act be used to inflate tires, using one would take more time and energy than most people would care to spend on the task, especially in the case of automobile tires. Most car owners look for automatic tire inflaters to handle the job.
Commercial tire inflators, like those seen at fueling stations, are usually much more powerful than an individual will need. They are designed to handle multiple vehicles very quickly. Still, for those who are working on cars, or who have collections of cars, a larger unit may be the best option. Generally, those who are going to be inflating a few tires on an occasional basis only need an inflator with a capacity of one or two gallons (3.75 to 7.5 liters) of air.
Another option is a roadside tire inflator. This is a very small air compressor that can either be plugged into a standard electrical outlet, or run off the electrical current in the car. The device plugs into the DC outlet, traditionally known as the vehicle's cigarette lighter. It will usually take longer than a standard air compressor, even a smaller one, but it is still capable of inflating the tire to the proper pressure. Most will also have an air pressure gauge built in so the user can see when the desired air pressure has been reached.
Some of these roadside inflators include other features. Most will have a flashlight, which may aid in finding the tire's valve stem in the dark, or be used for other emergency situations. Some will include a flashing yellow light, meant to warn oncoming motorists of a disabled car alongside the road. Some may even include a feature where the user can program the tire inflator to automatically shut off after a certain pressure is reached.
To help increase portability, a roadside tire inflator may include an onboard battery, making the unit capable of being used wirelessly. This battery can be charged so that it is ready to use when the emergency situation comes up. Those using this feature should use caution, however. Unused rechargeable batteries will lose their charge over time. Thus, even if it has not been used since the last time it was charged, it could still be drained of power. It is a good idea to recharge the battery every two months to make certain it is ready for use.