I don't run cars, so can't answer there. I can say they definitely do not cover boats. The ONLY way to confirm a boat engine (assuming it's driving a traditional boat prop as opposed to a plane engine on an airboat), has the right needle setting is to put it in the water and see how it runs. Boat engines should NEVER be run at high RPMs on the shore to try to tune them. Doing so is very likely to throw a rod.