I agree with Graham. A big air impact like he is talking about is under 100 bucks at Harbor Freight. If you are going to work on trucks and cars in the future, it's a wise investment. Many times the only easy way you can remove a crankshaft pully bolt or axle nut, or anything that is on a free turning mechanism is with a fast strong impact. I would shy away from the electric impacts becasue they are not fast or strong enough. My $.02
