air compressor for inflating tires

Go to the viair web site they have all the specs. I have the Viair 450p. Mine is the auto model. Great air compressor. When comparing compressors you need to compare pressure and cfm. The cheap ones just don't cut it. I use it to winterize on the road when temp drops below 10 degrees. Plus using it on tires. Check out Amazon prices.

Can you not use the on board air system to inflate your tires?

Hmm, we just bought a "Slime" cig lighter filler. :)