I'm one for redundancy, particularly when right off the beaten track. I have a twin compressor system mounted in a under tray bin. These feed to a custom built pressure tank of roughly 24 cf (a bit over 3200 Cubic Centimetres) capacity which is mounted under the tray body. I've found that the dual compressors make short work of airing up 33" and the big 35" muddies. The reserve is also handy for air tools and reseating tyres although the thicker walled off-roaders often require some more "non-traditional" methods to coax them to seat.
I also carry a portable Bushranger "Airmax" compressor as both a back-up, for use on the quads and where I can't get the ute close enough to the job at hand like another vehicle.
I also carry a portable Bushranger "Airmax" compressor as both a back-up, for use on the quads and where I can't get the ute close enough to the job at hand like another vehicle.