A:  This is outside of my specialty, but in general, yes, but only a little bit, as a lubricant. Oil (or grease) is used to lubricate lots of moving parts on the rides, like the lift chains and the wheel bearings. Do you know that long chain that grabs the vehicle and pulls it to the top of the first big hill? On most coasters, that chain is driven by a big motor in a little room, usually at the bottom of the hill. Just like a bicycle chain, that chain is driven by a sprocket that looks like a big gear. That chain rubs on a lot of things on the way up and down the hill. To keep it from wearing out, they keep a steady drip of oil on the chain while it is running. There is usually a little bottle of oil over the chain with a small hole in the bottom. Oil runs out of the bottle a drip at a time, and flows down on to a brush that touches the chain as it moves. It applies just enough oil to keep the chain from wearing out too fast.