Oil is used in the transmission and engine. The bearings and most sealed gearboxes use silicone grease. Lots of dampers use silicone oils. In consumer produc

Oil is used in the transmission and engine. The bearings and most sealed gearboxes use silicone grease. Lots of dampers use silicone oils. In consumer products and anything sealed, silicones are far more common and heavily preferred. PDMS for instance has rheological properties that make it almost flat out better; it spreads and covers surfaces extremely well. As a bonus it has better thermal and chemical resistance. Silicone rubbers are well known to have far superior mechanical and chemical properties than carbon-based rubbers. 99.9% of the time the only factor is cost. N-butyl and urethane have some advantages for certain chemicals, which is almost never relevant. Silicone plastics are at least as good as common plastics like PVC, ABS, HDPE etc. Fancier stuff like flouropolymers, definitely not. > Because you see car oil synthetics are preferred over mineral maybe? Is this some kind of gotcha you're trying to set up? Synthetic oils are not silicones. > Just ONE example off the top of my head, carbon fiber, is almost entirely oil. NB that I was specific- lubricants, plastic, and rubber. There is a composite made from silicon... Fiberglass. It's orders of magnitude more common than CFRP and in many applications s-glass is both stronger and lighter. Still bonded with carbon, of course. Overall you're responding to an argument that I am not making.