Our air starters on semi trucks also sound cool, but different than that, when I drove for CCX that is what we had . . . air starters run cooler, but if they don't start right away, or you have an air leak . . . your supply runs out faster than a battery . . . but you can "jump start" them with an air hose that goes to the trailer from another truck . . . if someone will stop . . . I once had a junker, with a bad clutch, and a small engine, with a heavy load, at a toll booth in MA I kept stalling . . . fortunatly someone came along with an extra hose, as I was at the window paying, and there was no room to pull up next to me . . .