Gasoline is a drop in the bucket compared to the manufacturing demand using hydrocarbons as a raw material for materials such as synthetic polymers.I didn't think this was the case. The Department of Energy's Energy Information Administration report on demand and consumption backs me up.
They estimate that approximately two thirds of US oil consumption is used for transportation fuels. Now this includes not just gasoline, but diesel, aircraft fuel, and heavy fuel oils for shipping. Gasoline itself accounts for 45% of total US oil use. This is not a drop in the bucket.