Here is what I carry around in our Sprinter. QuickAir with QD hose and fill valve. I mounted it in a metal QuickAir box with a switch and electrical hookup. Everything is in one place for grab and go. This pump is at least 7-8 years old. Still going strong and I have used it allot airing up Jeep tires 4 wheeling. This model is no longer sold but the newer ones look like good quality. You might also check the Jeep and 4x4 forums. Those guys really discuss portable pumps and onboard air allot.
Flow Rates:
2.18 cfm @ 0 psi @ 22 amps
1.76 cfm @ 20 psi @ 22 amps
1.45 cfm @ 40 psi @ 24 amps
1.20 cfm @ 60 psi @ 25 amps
0.99 cfm @ 80 psi @ 26 amps
0.85 cfm @ 100 psi @ 26 amps
0.77 cfm @ 105 psi @ 28 amps
Duty cycle rating:
40 min. @ 40 psi
15 min. @ 80 psi
5 min. @ 105 psi