Inflate Tires With a Portable Air Compressor

If you just need a quick and easy way to fill up car tires, bike tires or wheelbarrow tires, virtually any portable air compressor will do. Small, portable compressors, also called air inflators, have become a popular choice to fill a wide variety of tires, sports equipment and other inflatables in home garages. These compressors are also small enough to be stored in your vehicle in case of roadside emergencies. Most can run off household power, a 12-volt car plug or cordless batteries. Many compressors that can be kept in vehicles are designed to provide a continuous supply of air and don’t have a tank. This type of compressor is easy to operate. You just attach the air hose to the tire, set the recommended pressure in pounds per square inch (PSI) and the inflator automatically fills the tire to the set PSI.

Tires on most cars, crossover SUVs and pickup trucks normally aren’t very large and are usually filled to a recommended air pressure of around 32 to 36 PSI. But larger tires, such as those on service vehicles, farm equipment and RVs, often need up to 100 PSI. This may be too much for some portable compressors that have a lower operating PSI. If you’re just topping off a tire or two by adding a few pounds of pressure to each tire, a 1-gallon air tank should be plenty to fill all your tires in one charge. Portable air compressors in the 3- to 6-gallon size, such as those used to operate pneumatic nailers, are good for filling larger-size and heavy-duty tires. If you have a completely flat tire, however, it may take several cycles to refill the tire completely. The larger the tire, the longer it’ll take. For more information on large air compressors, read our Air Compressor Buying Guide.

If your tires are inflated at 5 to 6 PSI lower than they should be, inflating them takes about 20 to 30 seconds. A fully flat tire may take between three to five minutes to inflate, depending upon the size of the inflator or air compressor you’re using.

1. Check the air pressure in your tires. It’s best to do this when the tires are cold, meaning the car hasn’t been driven within the last three hours or so. Warm tires will give an incorrect PSI reading.
2. Connect the compressor to its power source — a 12-volt car adapter plug, 120-volt plug or battery, depending on the compressor type.
3. Connect the air hose to your tire. You need to have a filler tool, called a tire chuck, installed at the end of the air line. The tire chuck allows you to connect the air hose to the valve. Run the compressor until you think the tire has reached the suggested pressure, usually for just a few seconds. Some air inflators allow you to set the proper PSI for your tires and will inflate them to that setting.
4. Disconnect the air hose from the tire, check the tire pressure with a pressure gauge and add or release air until the pressure is correct.