I have a couple older guys in the shop I work at that swear that synthetic is "A thinner oil". Example: Tech 1: "Maybe we should put synthetic oil in this car. It might burn less(oil)." Old Timer Tech 2: "Nah. It would probably burn more. That synthetic is pretty thin." I have heard this from a couple different people. I try to explain that viscosity is viscosity no matter what type of oil. I was thinking that maybe syn IS thinner when it is -20 outside but that is exactly when you need it.