Corey,
The onboard air supply will air up your tires if you do not need too high a pressure reading. Most onboard air systems cut the compressor off at the 120 PSI to 125 PSI range, so if you are running 120 PSI in your tires like I do, it will not produce enough pressure to air up tires without modifications. However, if you are running 100 PSI, it will work if you have someone occasionally hit the brakes when the compressor turns off to keep the tank pressure close to 120 PSI, but it will take a little time.
Gerald