I used to live 1.5 miles from the Outback Extreme company, he is a nice guy. I have the magnum and am very pleased with it. The fact that it can safely be mounted under the rear of the vehicle, where the spare was originally, without being adversely affected by the elements is a huge plus as this means it takes no precious cargo space and doesn't over crowd the engine bay.
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@EvanD, while my 37's inflate from 12psi to 28-40 depending on load, meaning 2-3 minutes per tire, I give the 80 an underside inspection, eat a sandwich and stretch the old muscles out.
People were using A/C compressors long ago before a good 12/24V compressor was ever conceived. There is a reason we now have good electric compressors. I believe this is because they are less complicated add on to any rig, they don't need to clutter the engine bay and, 99% of the off-road community has no need for the amount of air a belt driven pump will provide.