Trail-Testing ARB’s Twin Portable Air Compressor

Verne SimonsPhotographer, Writer

Working for an off-road giant like Petersen’s 4-Wheel & Off-Road means we have spent lots of time airing tires up and down. Whether we are out testing new tires or new vehicles, getting to the trailhead to cover an event, or just out playing in our free time, airing down (and back up) amounts to a good block of time if you add it up over the years. The time to air down is consistent because the fixed size of a valve core only allows so much air out. Airing back up may be the one area where we can save ourselves any time at all, and equipment makes a big difference.

There are several options for airing up tires, ranging from the slow but inexpensive tiny compressors powered by the cigarette lighter to the fast custom and complex vehicle-mounted onboard air system driven by the engine. Also in the mix are portable and refillable CO2 canisters that are fast but, with use, need to be refilled. That gives our addled minds a chance to forget to refill, and that’s bad when we only realize it when we’re out on the trail.

Introduce the fact that we switch between multiple vehicles, and a portable system becomes much more attractive. But who wants to wait on a portable yet slow and unreliable parts-store mini compressor? In today’s modern age, can’t we have it all? We want a system that is portable and fast with a good battery and charging system and that provides a never-ending supply of compressed air. Some say yes. We are happy to check it out.

Enter ARB’s new CKMTP12 Twin Portable Air Compressor. With a compact and durable plastic case and a dual-cylinder, twin-motor design, this is the highest-flowing portable compressor of its size, producing 6.16 cfm. With aluminum motor mounts that act like heat sinks, this baby has a 100 percent duty cycle at room temp. Add an in-box compact air tank, and ARB claims this thing can run air tools. Portable? Fills tires fast? Runs air tools? We’ve got to test this out for ourselves.

The heavy-duty case base contains the compressor, wiring, and aluminum tank. The upper portion of the case has a fabric organizer that holds the air hose and fittings that come with the compressor. Oh, and an instruction manual—whatever that is.

The compressor has beefy clamps, and each lead holds a 40-amp fuse should you get your wires crossed.

ARB also includes this lock-on air chuck, an air duster, and these fittings for inflating your big comfy air mattress or that trail side basketball—or beach ball. The fabric organizer has extra space for a few air gauges and other items you might like to stuff in there. The price for the ARB Twin Portable is comparable to a well-built onboard air system. At just over $800 it is nothing to sneeze at, but it is portable, ready to go, and promises similar performance to that of many onboard air systems.

To test out the speed of the compressor, we pulled the valve core from one of our 37/12.50R17 tires and then timed how long the compressor took to fill the tire. 10 psi was reached fast, and 15 psi (what we would consider an average trail pressure) came up in just over a minute. At right around two minutes we had 20 psi and at 3.3 minutes 30 psi. Our Tahoe seems pretty comfortable on the road with around 42 psi in each tire, and our 37-inch tire went from no-valve-core flat to about 40 psi in under five minutes. To boot, the twin has a pleasing twin hum reminiscent of dual-prop aircraft.

Our last test, for now, was to hook the ARB Twin Portable compressor up to our angriest pneumatic impact. This Ingersoll Rand gun is our last resort when a stubborn bolt just won’t move. We don’t know how efficient it is at using air or the torque spec it will reach to break a nut loose, but we know it’s loud and strong. Hooked up to the ARB Twin Portable Air Compressor, the IR gun pulled our heavy-duty lug nuts without acting funny at all. The compressor just buzzed away, making more compressed air. Time and our abuse will tell whether the ARB compressor will hold up, but with a durable case and simple yet effective construction, we are expecting to use this compressor for years to come.