I am little disturbed and concerned by the maniacal laughter.LOL here is one reason because mine has twin-cylinders and yours only has one so in any conditions mine will fill the tire twice as fast as yours. Up at high elevation it makes an even bigger difference LOL Yes I did spend my own money on it LOL. Also...LOL...it has auto-shut off so you can just hook it up and forget until you hear it shut off then move to the next tire etc etc LOL just makes it easy LOL