Well, I went thru the same thing. I need my 22.5 inch Michelins at 100 psi ++, and I have found that a 12 volt compressor (any brand) just won't do it. I got a "truck rated" compressor, 150 psi, AC 120 volt. My 1800 watt inverter will easily run it, so I just plug into my RV, with fridge off. Otherwise, I would turn on my generator to be sure I have enough watts. In either case, it works. My XRV tires on the Miramar, 36 foot, seem to like about 105 psi. Other rigs will be different, of course. The only problem: the compressor is big and heavy. Hmmm.