When it comes down to it, your adventure vehicle is connected to the ground by four patches of rubber not much larger than the human hand. All those thousands of pounds of rig, gear, fuel, and human beings maintain their connection to the earth through your tires, and those tires are suspended only by a tenuous bubble of air.
Luckily for the overland traveler in the modern age, advances in tire technology have gifted us stronger and more efficient all-terrain and mud-terrain tires. They have more resistance to punctures and sidewall tears, and more ability to shoulder heavier loads over longer distances than ever before. Formerly exotic materials like Kevlar, which boosts durability, are now widely found in tire construction. With all the low-maintenance and high-performance off-road tires on the market, it’s easy to be lulled into a sense of security by their remarkable capability.
However, punctures, tears, and tire damage can happen at any time on and off road. There is one tool that every adventure traveler should have at their disposal, both to repair tire failures, and to prevent them in the first place.
The humble air compressor is here at your service.
Most of us are familiar with the kinds of simple air compressors that do their basic duty inflating basketballs and bike tires, or the more robust, large-tank air compressors that you find in professional shops and well-appointed personal garages that run power tools, sand blasters, and paint guns.
But there is a category of air compressor somewhere in the middle that is especially useful for the overland traveler - it comes in two forms and, for the cost on the high end of two quality mud-terrain tires, it could literally save all of your others. Not to mention that adventure that you planned so carefully, and which ultimately rides on four bubbles of air.
12 Volt Power
An air compressor is an essential arrow to have in your off-road quiver for a number of reasons. Not only will it inflate a flat tire, but it might actually save you from that flat in the first place. The compressor, like Patrick wrote, is one of your key front-line recovery tools. Proper air pressures are important not only for traction on the trails, but also for efficiency and safety on the highway.
Normally, for deep sand, mud, and harsh gravel roads with corrugations and sharp stones, we “air down” - reducing the air pressure in our tires to maximize traction and impact absorption. But, in reality, a majority of our travel miles, especially in North America, are spent on Interstates and state routes - the Blue Highways - and highway time is no time for low tire pressures. “Airing up”, or bringing your tires back into the manufacturer’s recommended pressures for normal road travel takes time, and it takes energy.
That rattley compressor you plug into the cigarette lighter in the dash may work in a pinch, but for repeated airings-down and airings-up that you might encounter on a long overland journey, a dedicated, high-power, 12 volt air compressor is the only answer. This is not only for efficiency’s sake, but also for safety’s sake. Driving for too long on paved surfaces with under-inflated tires invites failure by overheating those tires and damaging the internal structures that keep that precious air contained between the wheel and the rubber.
Portable Air Compressors
One solution is the portable air compressor. These come in various flavors, from the aforementioned lightweight cigarette lighter model that you can find in any box store, to robust, high-flow compressors that inflate even the largest mud terrain tires in minutes, like the ViAir 450P available in the Overlander shop.
Portable air compressors offer several advantages. As long as they can connect directly to your vehicle’s battery - either with alligator clips or quick-release attachments - they can be as powerful as most permanently installed on-board air systems. They are, by their nature, portable - you can move them between vehicles easily, and their flexibility means you can deploy them quickly in many different situations.
On the flip side, portable air compressors need to be hauled out and hooked up to power each time you need to air up, and you need to find dedicated storage space in your vehicle to stash them.
On Board Air Compressors
For the committed overland traveler, a permanently installed air compressor can be one of the most versatile and utilitarian tools at their disposal. ARB has built heavy duty and incredibly reliable on-board air compressors for decades. These units are wired directly into your vehicle’s central electrical system, or to an auxiliary battery circuit, and can be operated from a dedicated switch from inside the vehicle.
Drawing power from the vehicle’s battery and charging system, directly installed air compressors can run at high capacity for long periods, meaning faster air up times for your tires, and less of your trip spent on the side of the road waiting to bring them up to proper pressures. They also can do things for which portable air compressors aren’t designed. First among them is operating air-actuated locking differentials, like ARB’s Air Locker.
Air Lockers provide a flexible traction aid that ties your wheels' grip between and across axles by temporarily locking either the front or the rear differential (or both!) at the flip of a switch. Powered by the ARB compressor, the Air Locker can be deployed exactly when and where you need it in low traction situations, and turned off just as quickly to prevent wear and tear on your axles and differentials. It’s a time-tested and cost effective way to increase the all terrain capability of your vehicle.
But, on-board air is not just for tires and axles. With the correct attachments your compressor can run air tools, inflate kayaks, rafts, and stand-up paddle boards in no time, clean out engine compartments, and clear dust from roof top tent covers and other components and accessories. A direct-mount air compressor means that you do need to find dedicated space to mount the compressor itself. They are compact enough that there is usually space in your engine bay, but the wiring and fuses for power and switches also need to be taken into consideration.
No air compressor set-up is complete without the accessories that actually make it work for you - heavy duty hoses, various chucks and connectors, a tire repair kit, and a tire pressure gauge are all essential components. Overlander stocks a wide variety of air compressors from ARB, along with all the attachments you might need to keep your adventure vehicle pumped up and ready to roll.
What kind of conditions do you air down for? Let us know down in the comments! We love to learn from the overland community.
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