I use my portable 12vdc compressor to maintain a +/- 5 psi tire pressure at home or on the road (100 psi front/110 psi rear). I never let my tire condition get bad enough to need any more adjustment than that, if they do I replace them with new tires.
And yes, I need a portable 12vdc compressor to accomplish this.
Rick and Lynda Smith
2004 NEWMAR DSDP M-4011-SPTN 8.9 Liter Cummins
2011 GMC SLT 1500 4WD CREW toad