A Car Air Compressor is one of the most important pieces of four wheel driving equipment that you can carry. The only reason you shouldn’t carry one is if your four wheel driving locations are all within a few kilometres of a service station that is open whenever you are done.
Personally though, I much prefer to carry my own compressor. Take Lancelin for example, where the service station isn’t too far away from the dunes, but you can be waiting for an hour on a busy day for other vehicles to pump their tyres up.
What is a Car Air Compressor?
A Car Air Compressor is basically a small version of the compressors that you see at a petrol station. They are designed to fit inside of your car (in fact they are smaller than a shoe box) and can be used to inflate your tyres. These vary considerably depending on what you want, but they all suck air in and pump it into the tyres.
Why do you need a Car Air Compressor?
When you drive off road you should be deflating your tyres. This aids in traction and makes the ride smoother. It also makes it safer and puts less stress on your vehicle and the environment. In sand, most people go down to around 15 PSI, and you should not be driving on bitumen with tyres that are so low. The reason for a Car Air Compressor then is simple; to pump your tyres up when you are done four wheel driving. Usually this is just before you get onto a bitumen road, but it may be when you are changing terrains (from sand to corrugated gravel for example). Remember to get a compressor hose that is going to reach your trailer, if you are towing a Camper Trailer or Boat!
Deflating your tyres
Letting air out of your tyres is one of the most important things to remember when four wheel driving, especially Beach Driving and when you are driving in sand dunes. One of the main reasons that people get stuck off road is because they don’t let their tyres down enough. I will leave my ‘Tire Deflators’ post to cover the bulk of this, but as a summary letting air out of a tyre you make more of it touch the ground. This in turn gives you more traction, which is vital for four wheel driving.
How much you let out of your tyres should be determined by the weight of your vehicle, the size of your tyres and what you are driving on. In general though, sand driving should be between 15 and 18 PSI, gravel driving between 22 and 26 and rock crawling in between 15 – 18. Of course, this is only a rough guide. If you have a vehicle that is exceptionally light weight then you should be going down lower, and if your vehicle is very heavy then you might want to keep the pressures higher.
Types of Compressors
Car Air Compressors are usually mounted to the vehicle, or they are left as portable. Both have their advantages. Most people will purchase a Car Air Compressor and mount it to their vehicle. From there, you just plug in the air hose and turn it on. These come in many different sizes and qualities, and of course the prices vary considerably. A good compressor will pump the average four wheel drive tyre up in about 2.5 minutes, but then even a cheap one will only take 4 minutes or so. Obviously this varies depending on the size of your tyres!
Purchasing a Car Air Compressor
Four Wheel Drive shops are the most common place to purchase a compressor for your car. A lot of these sell online too, but be sure to get something that has a good reputation. I know that there are a lot of cheap quality compressor’s out there that are simply a waste of money. In saying that though, often eBay is a good place to look!
Where can you mount the compressors?
The most common place to mount your compressor is in the bonnet, however I suggest that you don’t do this for a number of reasons. To start off with, compressors get quite hot and keeping them in an environment that changes temperatures regularly is not a good idea. When you go to use your compressor it will already be hot. The engine bay often gets wet, and as you know dumping electrics into water doesn’t generally have a good outcome. The engine bay also gets filthy, which is bound to clog up the compressor and make it break quicker.
Instead, you are much better off mounting the compressor inside of your vehicle. Have a think about where you could put it and you will surprise yourself. Mounting it under a seat is common, or in the back panels behind the plastic trim. There are plenty of spaces that you can mount them which will keep them dry, cool and easy to access. Still, having them in the bonnet can be convenient and it is a very common practise.
Air tanks for Car Compressors
If you hate waiting around for your tyres to pump up, you can install air tanks under your vehicle. When you are almost finished four wheel driving you can turn the compressor on. This will pump air into the tanks, and then you can use that ‘instant air’ to pump up your tyres quickly. A lot of people will put these in between the chassis and rock sliders, but you want to find somewhere that is out of the way. These basically eliminate the time wasted whilst waiting for your tyres to pump up. The air tanks can usually hold a fair bit of air, meaning you get to pack up and leave much faster. Generally people who add air tanks have huge Mud Terrain Tyres like the Maxxis Bighorn because they take so much longer to pump up.
Driving on Bitumen with low Tyre pressures
If you have to drive on Bitumen on low tyre pressures, try to keep your speed down. The reason for this is quite simple. By having your 4×4 Tyres deflated you are increasing friction, which means the tyres get hotter quicker.
By driving fast you will heat them up quickly and then the rubber starts to peel apart and you throw several hundred dollars down the drain (or more depending on how many tyres you damage!). Tyres that are more aggressive tend to cool easily, but you still want to avoid driving on bitumen with low pressures. It really isn’t worth driving on bitumen with low tyre pressures – spend $100 dollars and get an air compressor.
What Car Air Compressor is good?
When you want to purchase a Car Air Compressor, have a look around for something that matches what you want. For example, if you are going touring in the middle of Australia purchasing the cheapest compressor available would not be a smart decision. If you regularly pump your tyres up then you want something that is going to do it quickly. This is especially the case if you have large tyres (the difference between 31 inch tyres and 35 inch tyres makes a huge difference!).
I have a Bushranger Power Air Series 2 which you can purchase at most automotive places for $100 dollars. These are about the cheapest, decent quality Car Air Compressor available. They are portable, meaning you don’t mount them to the vehicle and they work very well. They don’t pump tyres up the fastest, but they have been proven to be able to pump for a long time without suffering any issues. In fact, 4WD Action rated them as the best budget compressor that was reviewed (and they reviewed quite a few!). The ARB Compressors are rated to be one of the better ones, but not everyone is happy with them. At the end of the day, shop around, look for reviews and find something that you are happy with. In terms of all of the 4×4 Accessories that I have purchased, I would suggest that a good Car Air Compressor is the most important. Tyre Pressures make such a big difference when you are off road.