Tire deflator history 101
When I first started four-wheeling more than a decade ago, tire deflators did not exist. If you felt the trail was difficult enough to air down your tires you simply used the tip of a screwdriver to push in the little stem and let the air come out. If you have ever tried to do it this way you know that it takes almost forever to do.

In an effort to speed things up guys started bringing valve stem pullers. This seems like the fast way to do it. The air comes out fast, but you have to screw the stem back in every time you want to check pressure and it is very easy to let them go too far. Today there are all kinds of tire deflators on the market ranging in price from $10 to 5 Billion (or whatever the government pays to have an onboard deflation system on a Hummer). What is right for you depends on how much you want to spend and how much work you want to put into it.

Things that make you go “Hmmm”
Last year, someone stole my $10 tire deflators out of my Jeep. Two weeks later we found ourselves at the SEMA show in Las Vegas, NV watching a demonstration of “Staun Tyre Deflators.” Our first response was “Hmmm, those are kinda cool.” The word “Tyre” also caught our eyes, as we listened to fast-talking Lee Davis, the Australian who designed them ,tell us all about them.

The whole idea of the Staun Tyre Deflators is that you can preset the air pressure you want to run and then lock them so that you can rapidly air down to that pressure every time you use them without having to fiddle with a pressure gauge.

How do they work?
Each brass tire deflator comes preset at 18psi and can be adjusted from 6-30psi. There is an adjustment cap and a lock ring to hold the cap in place. Each ½ turn of the adjustment cap decreases that setting by 3psi. Once you have set the pressure that you would like to deflate to, you can tighten the lock ring to keep them at that pressure for future use. You can also set the deflators by using a tire that is already aired down to a desired pressure. Simply screw the deflator onto that tire and turn the adjustment cap in until air just barely escapes. You are now at the desired pressure and can tighten the lock ring to keep them set there. You will have to do this for all 4 deflators. Since each ½ turn of the adjustment cap is 3psi of air you can use this to adjust to different pressures for different trails. I set mine at 12psi and left them there. Staun can also manufacture the deflators with custom valve settings.

Screw them on and forget about them!
Made in Australia and distributed by TJM Products in the US, the deflators come in a set of four for around $60 and include a handy storage pouch. You just screw one onto each valve stem and forget about them. In about a minute all your tires will be aired down to the right pressure and the tire deflators will shut off. Other deflators on the market will not stop and will continue to air down until the tire goes flat. With the Stauns you don’t have to run around your truck stopping your deflators and checking your pressures until you’re at your desired pressure.

It is pretty nice not to have to squat next to each tire and check it every few seconds to see what the pressure is. With all this extra free time you can disconnect your sway bar or help your friends air down their tires. Just don’t forget to take the tire deflators back off when they are done airing down your tires to avoid damaging them. Because they are so easy to use, I have done this more than once.

If you’re looking for a no-brainer way to air down your tires – or tyres, you owe it to yourself to take a look at the Staun Tyre Deflators. Quick and easy to use, they’ll have you aired down in no time.

Staun Tyre Deflators are available in the US at www.HummerHub.com/Staun_Tire_Deflators

Update! Between the time we received our Staun's for review and posting our story, there have been a few improvements in the design. According to Lee Davis at Staun,
"The main change comes from the change to the plastic T piece. This is now what we call a T piston, which is machined in brass instead of the cedal plastic. This allows us to machine the brass at finer tolerances, therefore giving greater accuracy.

The chamber is 4mm deeper than the previous valve which allows for a bigger adjustment range, now 6-35psi.

The valve shuts of much cleaner, with a crisp snap as is closes at the preset pressure. This truly is a life time product, there is nothing in the product that we see can fail if kept clean and dry."

Resource:

The bigger the footprint, the softer the surface you can travel on as the weight of the vehicle is distributed over a larger surface area. When tires have very little or no traction they have a greater chance of getting bogged down or stuck in the surface or terrain that they are being driven through.

Tests have shown a 40% improvement in overcoming obstacles at lower tire pressures due to the low pressure tires being able to contort over the obstacle. Therefore the drive becomes a less bumpy, much softer ride.

Fuel usage increases when tires are at higher pressures because more revs and greater acceleration is required to take the vehicle over the off-road surfaces.

The increased surface area of the tires enables the vehicle to be stabilized at higher speeds on softer surfaces.

Well before that, if you look closely at the back tires of our Hummer H2, you can see that they are very low on air. When off roading on the sand, we use our Staun Tire deflators to deflate to about 15 PSI so that we can get better traction, a must on the sand. Our 2003 Hummer H2 is equipped with a built in air compressor, but we rather use a Power Tank. Using the built in compressor, would take at least anhour or so per tire to inflate to 35 PSI, so what do we use to inflate to the necessary tire pressure? Power Tank. You can inflate back to 35 psi in 30 seconds or less.

The Dangers ofLeaving your Staun Tire Deflators on While You are Drivig.

Just don't, take your Staun Tire Deflators OFF.

A common question about tire deflators is "Can I leave them on while I am driving?"And the answer is "Yes you can, BUT only if you want to take certain risks." The biggest danger of driving with deflators still attached to the valve stem is that the tire could deflate fully. This can cause the tire to come away from the rim, which can result in an accident occurring with potential fatalities.

Another reason to remove deflators before driving off road is the potential for the valve stem to snap. Once a deflator is screwed onto the valve stem it becomes an extension of that stem.

Therefore, if you were to knock the deflator with any obstacle, you could snap the valve stem at the rim causing instant deflation.The other major risk is that debris, such as sand or muddy water, can pollute the chamber and prevent the deflator from sealing.