The Best Air-Down Tools for Overland Adventure

As we embark on four-wheel drive adventures through the backcountry, it’s common practice to release air from our vehicle’s tires, which we do for the following reasons:

Improved Traction

Airing down dramatically increases the size of a tire’s contact patch; the surface area of the tire that is in contact with the ground. This dramatically improves traction in all circumstances, and aids in flotation over granular surfaces such as soft sand.

Driving Comfort

Primitive road surfaces can be bumpy, varied, and jarring. Significantly softer tires better absorb rough and rocky terrain, and can make an otherwise miserable journey very relaxing, and thereby reduce fatigue. For this reason, I’ll air down for mere gravel roads, even when improved traction is not essential.

Puncture Resistance

Fully inflate a party balloon and poke it with a wooden toothpick. It’ll likely pop straight away. Now partially inflate another balloon, and give it the same poke. The rubber has more give, and it doesn’t rupture as readily. The same concept applies to tires.

Tires with low air pressure offer maximum traction, comfort, and durability

What pressure should I air my tires down to?

Airing down is not an exact science, and how much air you should release depends on your tire and wheel combination, vehicle weight, terrain, and personal preference.

I consistently take my 6000 lb Jeep Wrangler down to 15 psi on all four corners, equipped with 35″ tires, load range C, on 17″ wheels. This feels about right for most off-highway adventures.

I’ll take our 11,000 lb Mercedes Sprinter down to 25 psi, equipped with 31″ tires, load range E, also on 17″ wheels. This makes a world of difference for this vehicle’s comfort and capability on rough driving surfaces.

Sometimes, I might only remove 10 to 15 psi from my tires if I know my route will frequently alternate between paved and unpaved surfaces. This will slightly improve comfort and capability, but the tire pressure won’t be so low that driving at highway speed is unsafe.

IMPORTANT: While you can drive on pavement with low tire pressure for short distances, soft tires adversely affect your vehicle’s handling characteristics, making it is unsafe to drive at higher speeds. If you need to return to pavement for extended driving, re-inflate your tires to street pressure as soon as you are able.

What are the best tools for airing down?

There are many different tools and techniques with which you can quickly and easily air down your tires. In the end, it comes down to personal preference. However, one thing is certain – using your ignition key to release air from your valve stem is out of the question. That would take forever!

I’ll get to the technique that I use at the end of this post, but first, here are some options:

ARB E-Z Tire Deflator

This is a compact tire pressure gauge fitted with a short hose and a core removal assembly. It utilizes a mechanism that enables you to unscrew the core within the valve stem which then grants rapid pressure release. The assembly traps the core, preventing its loss, while allowing you to operate a brass plunger and manually regulate the amount of deflation.

It’s a very practical piece of kit. It’s safe, compact, acceptably quick, and right at home in your glove compartment. This is the sensible tire deflator that I would recommend for enthusiasts seeking a simple, reliable solution.

That being said, this isn’t my preferred air-down tool. More on that in a minute…

ARB E-Z Deflator in operation
ARB E-Z Deflator in its canvas pouch

Staun Tire Deflators

These are elegant brass assemblies that you screw onto your tires’ valve stems when you’re ready to leave pavement. They gradually and automatically release tire pressure until the tires are deflated to a set amount. Each deflator can be configured to release a certain amount of pressure using a threaded adjustment ring, with some trial and error.

The nice thing about these is that you can use them while you’re driving, effectively airing down while in motion. Simply screw them onto your valve stems, and off you go!

Staun Tire Deflators
Staun Tire Deflator Installed

I have a set of these, and I’ve only used them a few times. The trouble is, they’re quite prone to mis-adjusting if they’re mishandled, or jostled while in transit. This might cause one or two tires to not deflate to the desired pressure, which gives way to distrust in the gadget. While this is resolved by re-tuning the offending deflator(s), it’s not worth the time and effort when there are more reliable ways to air down.

To their credit, when they work as expected, they are wonderfully convenient. This makes them a decent option, and if you have the patience to make occasional adjustments, you might be very pleased with them.

Fast Deflating Valve Stems

These are replacement or supplemental valve stem assemblies featuring a gate mechanism that grant an extremely rapid release of air pressure.

I’ve seen these in operation, and they’re very impressive. You can deflate your tires from street pressure to trail-ready in as quickly as a few seconds. The volume of air that is released is almost akin to having a catastrophic gash in your tire. It doesn’t get much faster!

Rapid Deflation Valve Stem

Although they’re ingenious, there are a few factors that make me reluctant:

Rubber is King

Any fixed metal valve stem that comes in contact with the terrain is going to be irrevocably bent or damaged. While rubber valve stems aren’t impervious to being smashed or severed, they are extremely forgiving and more capable of deflection. If your use case is such that your wheels occasionally come in contact with the terrain, I’d avoid specialty valve stems.

Fitment Challenges

Your wheel type and style need to be carefully considered. I believe these are engineered to work with most wheels, but since it is a more complex mechanism than your standard valve, angles and clearances need to be confirmed.

Random Tire Shops

With specialty valves such as these, I’d be somewhat reluctant to take my vehicle to popular chain stores for tire work. Unfamiliarity might give way to problems.

These rapid discharge valves might be a great option if your preferred terrain or driving style is relatively subdued, and you have most of your tire work done by a savvy outfitter.

Multi-Hose Deflation System

Such a system utilizes two-to-four 10′ hoses, connecting them to multiple valve stems, which then converge on a pressure gauge. At the base of the gauge, the user is able to actuate the release of air pressure on multiple tires simultaneously. The reading on the gauge should then reflect the equalized pressure of all connected tires.

Four Hose Deflation System

While it’s clever and likely very satisfying to manage multiple tires at the same time, I cannot fathom how this cumbersome kit would offer any worthwhile gain in convenience. There are other ways to quickly and efficiently release air that don’t require the storage space consumed by 20-40 feet of hoses.

To be fair, such an accessory also enables you to air up multiple tires simultaneously, which is a somewhat more attractive use case, but in my opinion, the bulk and complexity exclude it as a serious solution.

From the checkout aisle at Autozone

Do you have five minutes?

Because that is the time it takes to air down four 35″ tires, from 32 to 15 psi, with a core puller and pen gauge that you can pick up at your local auto parts store for $1.50.

These are the exact same tools that I’ve been using to air down my tires since the 1990s, and every time I try a new gizmo, or something that is supposed to be better, I keep reverting to this simple technique.

Basic air-down tools
Remove the valve stem core

Address one side of your vehicle (two tires) at a time.

With the core puller, which is shaped like a little screwdriver, unscrew the core from the valve stem, and keep the removed core pinched firmly between your thumb and index finger. Allow the tire to howl and whistle for around 20 seconds while it gushes air, then repeat the process for the other tire on the same side.

For a few moments, the two tires will be releasing air simultaneously, and you’ll have both valve cores pinched between your fingers.

Pinch the cores to avoid loss

As deflation progresses, check the pressure of the first tire with your gauge. When it’s at the desired air pressure, replace the valve core, and then move on to the second tire. Check for the desired pressure of the second tire, and replace the valve core when ready.

Repeat this 2.5 minute process for the two tires on the other side of the vehicle.

The air-down industry is wrought with solutions in search of problems. While all of the aforementioned tools and techniques feature some degree of merit, it all comes down to your personal preference. If anything, take away that the state of the marketplace does not imply a need for specialty equipment, and that simple solutions can work just as well.

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