A portable air compressor is a must-have accessoriy for any 4wd owner. The more off-roading you end up doing, the more use your air compressor is going to get. Adjusting tyre pressures to suit the terrain is key when it comes to successful 4wd in the outback. A portable air compressor is require to inflate your tyres again when you hit the bitumen!
A compact, lightweight air compressor should be carried in your vehicle at all times. You never know when you might need one. If its inflating your tyres after a repair or adjusting your pressures to suit the terrain, a portable compressor will be very handy.
With the right attachments you can also inflate camping accessories such as matresses and inflatable boats.
If you're in the market for an air compressor, dont be tempted to buy any old cheapie at the supermarket or auto store. It just won't suit the task of inflating a 4wd tyre at all. 4wd tyres are much larger than normal car tyres and need a lot of volume to fill up.
There's a number of features you should be looking for when you go to buy an air compressor for your 4wd. Not all of them are related to the performance of the compressor, but you dont want to have to sit around waiting for an hour as it attempts to reinflate your tyres to road pressures after a day at the beach. If you're running big rubber on your truck, it's even more essential to have a high performing air compressor.
Some things to look for when deciding on your air compressor are air flow capacity, maximum operating pressure, maximum ambient temperature, duty cycle and whether its fitted with a thermal protection switch.
Air flow relates to how fast the compressor can inflate a tyre and is usually listed in litres per minute at a specified pressure. For example a compressor may be rated at 150lpm at 30psi.
Keep in mind that some compressors are rated to deliver a high volume of air at a relatively low pressure for tyre inflation. Others will be rated at low volume of air at a high pressure for air lockers and air tools.
To get an idea of how compressors compare with each other in performance, have a look at the airflow claims and see which one comes out on top.
Maximum operating temp is straight forward. It relates to a compressors temperature before it overheats. Many good compressors are rated at around 70 degrees C. They will easily operate in extreme temps such as deserts in summer.
Duty cycle is all about how long it can operate before requiring a rest. It is usually listed in minutes at a certain temperature. eg. 45min at 45 deg means it will operate for 45min before having to stop and cool down.
Some compressors have a continuous duty cycle, which means that they can operate indefinitely up to their maximum ambient operating temperature. These compressors will usually be fan-cooled units, but not always. Some units will also have obvious cooling fins that are designed to dissipate heat.
A thermal protective switch is a feature that ensures the compressor will switch off when it reaches its maximum operating temperature. This prevents the compressor getting damaged. Most manufacturers will list the temperature which the switch will activate.