There are numerous benefits to airing down your tires when driving off-road. As I've written about before, the obvious improvements that every 4wheeler knows are ride quality and traction. What fewer people realize is that tires are more resistant to punctures at lower pressures.
Cooper Tires teamed up with Australian 4WD Action Magazine to demonstrate the dramatic difference that tires of all types realize at various pressures. To accompany the article, they produced a video that illustrates the testing procedure and its eye-opening results:
Obviously, a tire with heavy-duty construction will be more puncture resistant than a light-duty tire, but owners of all pneumatic tires benefit from proper inflation pressures. I continue to be impressed with the ease (and more importantly, the accuracy) of the Staun Tyre Deflators I use. I find that I'm much more likely to air down when it's so quick and convenient to use these deflators. They have never failed to shut off at their exact pre-set pressure.
Just don't forget to air up again before hitting the highway! There are countless compressors that are available for the offroader, from the inexpensive but decent MV-50 to converted York engine-driven compressors, but the best combination of cost, power, and simplicity is the Puma Compressor. I've been using this for nearly a decade, and its combination of a fast compressor and a 1.5-gallon pressure tank allows me to very quickly inflate all four 35" tires (plus my two trailer tires!) faster than anyone else in my 4wheeling group can typically inflate two. Additionally, the blast of air that's provided by the pressure tank is sufficient to reseat a blow bead.