One of the most important tools to have off-road is some form of air pressure. Having on-board air makes re-inflating tires from trail pressures more convenient, helps deal with tire punctures and broken beads, and some can even run air tools. There are several options in having air pressure on the trails and they vary in cost, speed, and ease of use.
The simplest of the options is a high volume DC portable compressor. These hook directly to the battery and store away in their own case. They range in cost from about $70 to $300 depending on quality and the volume of air they produce. At the bottom of the spectrum are those like this Harbor Freight model http://www.harborfreight.com/12volt-150-psi-compact-air-compressor-69285.html. At the high end is this VIAIR, http://www.viaircorp.com/440P.html that can inflate 4 35” tires from 15 to 30 psi. in under 10 minutes. If you look up the specs, you’ll notice the HF model has a rather anemic 1.35 cfm (cubic foot per minute) while the VIAIR has over 2X the volume at 3 cfm. Trust me when you’ve been wheeling all day the extra speed of the more expensive compressor can sure be worth the price.
The next option for air compressors are those that are mounted permanently into the vehicle (on-board air). These can be broken down into 2 categories: DC electrical and belt driven. Hard-mounted compressors are particularly popular due to the usage of pneumatic lockers, which are required for their operation. For those such as the ARB air system, the compressor plays double duty as it actuates the lockers and can be used for tools and airing up tires. Belt-driven compressors are less popular, but are some of the least expensive options due to the fact that most are made from used parts found in a salvage yard. The simple idea is to convert one designed to compress Freon for an air conditioner to one that compresses air for use with lockers and tools. The onboard compressors have the advantage of being able to add an air tank for extra storage and even plumb air lines to convenient locations.
The final type of compressor isn’t a compressor at all, but a large air tank filled with liquid Co2. Co2 has the unique property of expanding to multiple times its own volume when it goes from a liquid to a gaseous state. This allows a single tank (about the size of a scuba tank) to hold Co2 that will fill your tires repeatedly, run air tools, and even actuate pneumatic lockers on a single fill. The most popular brand is Power Tank http://powertank.com/products/sfID1/13/productID/76 but there are other brands and I’ve even seen some home made Co2 tank setups that work the same and at a significantly lowered price.
Each of these options have both advantages and disadvantages; being informed is the key. Considering the importance of air pressure, this can even be considered a safety issue. Having a source of air pressure when you are out in the wilderness can be the difference between getting home on your own power or hiking miles to the nearest road. I highly recommend making at least the minimum investment to have a functional, high-volume air compressor in your Jeep.
*Jeepwithkids is not affiliated with Harbor Freight, VIAAIR, Power Tank, or ARB, but we sure think they have cool stuff*