Check out this 12 volt compressor that's on sale at Parts America (Advance, Checker, Schucks, Kragen). It puts out 72 Liters Per Minute and pumps up big tires WAY quicker than those cheap $15 junkers that plug into the cigarette lighter and that can only pump up a 35 in about an hour. Here's an online review that sold me on it. In this test it outperformed a $250 Quick Air compressor. I was gonna buy one of these for $50, then a buddy told me about the $25 sale price. I jumped on it and thought I'd share! This thing ROCKS!!! Pretty impressive, especially for just $25! It isn't nearly as noisy as my old POS that a) plugs into the cig lighter and b) takes 20 minutes to air up a 30-inch tire. It also has WAY less vibration while it's running. It stays in one place while running, unlike my cheapy that dances around until it reaches the end of either the power cord or the air line. It seems to be a pretty solid unit. 8) Note that Pep Boys carries the same compressor as the Master Flow MF-1050, but they don't have it on sale. It'll set ya back $50 there.