Tires must be kept at the right pressure to function properly. Under-inflated tires are dangerous because they reduce car handling, especially in wet conditions. They also cost more to run because they lower fuel efficiency, and have a reduced life due to abnormal wear. There are a surprising number of products available for the simple task of inflating a tire, and the number grows every year. Along with the common inflator unit found in every service station, there are also portable compressors, and even canned tire inflators for roadside emergencies. With so many competing products, deciding which one to buy is a difficult choice, so it helps to understand a little more about them.
The typical tire inflator unit has a handle, trigger, nozzle, and pressure gauge. The hose from the compressor is connected at the handle, and the nozzle is pressed hard against the tire valve. When the trigger is pressed, compressed air flows through the inflator and into the tire, with the gauge showing the pressure inside the tire. The two types of gauges commonly used are the pencil and dial. The pencil gauge is a rod with pressure values that moves past a fixed marker as the pressure changes, while the dial gauge is just the standard rotating needle gauge that everyone is familiar with. The advantage of these two gauges is that they only use the energy of the pressurized air. Some units have a digital gauge which is more precise but requires a battery, and that needs to replaced every so often. Since the nozzle needs to be pressed hard against the value to prevent leakage, it helps if the nozzle also has a hand grip.
Portable units that incorporate a small compressor and tire inflator are very popular, especially with owners of recreational vehicles and four-wheel drives. These compact units are essential when traveling in remote areas where service stations are infrequent. Some even have flashlights and radios, and can also be used for air mattresses and inflatable boats. These low volume compressors can take several minutes to inflate each tire but they can be left to run unattended during this time. When buying a portable tire inflator, check that it have enough cable and hose to reach all four tires when plugged in. Some units come with alligator clips for connecting directly to the battery terminals, while others have a plug that fits into the lighter socket.
Many vehicles don't carry spare tires so canned tire inflators are useful in providing enough travel time to reach a service station, or even to get back home. These products resemble ordinary aerosol cans but have a long nozzle attached to the top. They are filled with a compressed gas, and often have a sealant compound that helps block any punctures. They are non-flammable and are safe to store inside the trunk, and they are available in various sizes to suit most types of vehicles. Canned tire inflators have been criticized in the past because of the sticky residue they leave inside the tire, and some have changed to water soluble sealants because of this.
Inflating tires at a service station is one task many motorists would like to avoid. This task can now be done at home for a reasonable price by purchasing a tire inflator and a small compressor. Portable compressor units are a great accessory to have when traveling and can be used to inflate other camping equipment. Along with a canned tire inflator, they also make a handy backup in case the spare tire is missing, or has not been repaired since the last flat tire.