In The Desert
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Why would you want to air down?
Other interesting facts you should know.
Here are several reasons for "deflating your tires" in the desert, (otherwise known as "airing down"). Now if you've never done this on an off-road trip, then you might be missing something. But what? A smoother ride on rough washboard roads is the first thing that comes to mind. More traction in climbs and on rocky sections. Easier on your vehicle's steering and suspension components. Once you've "aired down" on a washboard road you won't ever want to drive it again with normal tire pressure. But there are a few words of warning that go with this and a few precautions you'll need to take.
Normal driving tire pressure is shown on the left and "aired down" on the right. This only takes a few minutes to "air down" and not more then 15 minutes to air back up for driving on the highway. It's important that you don't drive for long distances at highway speeds on deflated tires as this can greatly heat up and break down the sidewalls of your tires. So you will need a way to get them back up to normal driving pressures.
This is the VIAIR 90P Portable Compressor. It sells on Amazon for $75.74, at the time this article was written. We highly recommend it because it hooks directly to the battery (no blown 12V outlet fuses), it is a 120 PSI compressor, has a 12 ft. power cable and a 5 ft. inflation hose. So no more pulling on a coiled hose and the gauge on the compressor is right next to the tire your inflating, and the air hose is a clip on, not a screw on. There are cheaper units, but make sure you get one that's convenient and is going to work. See the Amazon Store link for more info and pricing.
If you are just going off-road to sight-see or take photos, and not to go rock crawling, then you need to be careful about the air pressure you end up with. On a sharp turn when "aired down" to less than 10 or 15 lbs pressure you could roll the tire off the bead on the rim, causing a roll over, We know of this happening once and an older couple ended up down in a canyon with a totalled Jeep after 14 roll overs. Not what you want to happen. We never went below 15 lbs and our normal highway pressure was 32 lbs. But yours may be different you need to ask others. Rock crawlers, for the most part use a special rim, called a "bead locker" to keep this from happening (see below). Really soft sand may require lower pressures to keep you from getting stuck.
Here's an example of a tire with just the right amount of pressure for off road travel. This will soften the ride and make sandy washes much easier to navigate. See below for more on this.
Tire tread examples: left is tread at normal highway pressures, right one is "aired down" for off-road use. Now a lot of people don't realize that the tire gets elongated more so than wider when "aired down". This gives you more traction and softens the ride.
Mouse over the photo of the tire to the right and you'll see one of the disadvantages to being "aired down". Easy to puncture a sidewall? When "aired down" don't drive over brush and sharp rocks.
The rim shown here is a bead locker, the outer plate bolts the tire on to the rim.
There are more than a few brands of deflators on the market. Our experience after seeing others "air down" is that the Staun Deflators (made in Australia) and sold at a lot of different sites on the Internet are the best ones available. Once set, they stay set, and are easy and reliable to use.
Also, you may notice that you've lost almost an inch of ground clearance when you "air down" compared to staying at full highway pressure. Not usually a big deal, but something you should consider. Driving in sandy washes is much easier and crawling up steep inclines is also easier to do at a slower speed because of the added traction. Some say it even increases gas mileage off-road, I'm not sure that's true and have never tested it. It does add a little time to a trip, but in our opinion it's worth it. The smoother ride is worth it if nothing else mattered. It's very important that you remain cautious where you drive when "aired down". We spent one miserable day in the middle of nowhere by ourselves with a small 1 inch diameter stick from a bush stuck into our sidewall. It ripped open a big enough hole that it couldn't be temporarily patched. It was over 110 degrees that day and you could not handle the tire iron or jack without having gloves on. Laying in the hot loose gravel wasn't any fun either.
If you go off-road with one of the clubs, they'll probably all stop on the way out to "air down". So should you do this? It really depends on how much time you spend in the desert off-road and how much comfort you want and if you need the extra traction in the rocks and sandy washes. Having an air supply is always handy if you get a flat.
Either way have fun ------
Airing Up, 12V Air Compressors
Air Tanks, CO2 Tanks
Why CO2? Simple it is an inert gas that will cause no damage to tires, rims, air tools, etc. It has the advantage of maintaining full pressure right up till it runs out. It also holds More volume than air or nitrogen gas. A 20 lb. tank holds 2,000 lbs of gas in liquid form and dispenses it as a gas - CO2. On the hottest days the regulator and part of the hose near the tank may freeze. But this has never caused us any delay. This tank should be mounted and secured in an up right position as shown here. The 20 lb. tank will fill 4 large tires about 16 times from 15 lbs. back to 32 lbs. We used to pay $17 to refill a tank. Prices and availability may vary. We sold our tank because there is no place to refill a tank anywhere near our home. So look into this before you buy one See the chart below. These are for serious off roaders who venture out a lot.
We bought our tank, hose, regulator brackets, and air chuck. It was less expensive for a 20 lb. unit. However you can buy a 10 lb. unit like the one here for around $330 complete. Adding a bracket made for the tank is also inexpensive. Just check to make sure a gas/welding supply business or a beverage company near you can reasonably refill the tank. If not then consider a 12 V compressor.
This chart will give you an idea of what to expect from a 10 lb. tank.
Our programer on the in the desert staff has offered some advice to us for this article. We're always open to more information and Ron is an avid off-roader. He has recommended that "Airing Down" tires should not be done with stock tires offered by car manufactures because of the extremely soft sidewalls which certainly would be prone to a puncture. This procedure is meant to be done with off-road tires and manufacturers today are supplying off road vehicles with highway tires.
Ron had a Jeep Rubicon and at the time had this VIAIR Constant Duty on Board Air System mounted in his Jeep. He said this unit worked great. It has a 100% duty cycle and an output of 100 PSI and is made for tires 37" or bigger. Please see the link to the right for more on this on-board compressor. Sounds great. And the price is not bad either.