Oil consumption

Over on the Guardian’s Notes and Queries site there is this question and answer.

In short the question is whether road, sea or air transport uses the most oil, and in what proportion. The only “answer” (which isn’t really an answer to the question asked) is that most oil is used in production of plastics. Sounds wrong to me.

What is the correct answer to the question, and is the “answer” given correct?

It’s probably something that depends on how you break it down. Plastics may take more oil than any single transportation category but I’d water that use of oil as energy is far bigger than use as a material.