Natural Resources committee  The best example is what we call vapour pressure. For your car to start, you need some vapour to start the ignition. As the weather gets colder, it's more difficult to have this vapour. The best example of vapour pressure is summer and winter conditions. You have to prepare what we call the base stock gasoline in the refinery with different components so that the vapour pressure meets the Canadian specs.

Natural Resources committee  As a complement, building a refinery is a 40-year endeavour, as a minimum, in terms of looking at returns over a long period. An economist would tell you that by and large this business is roughly an 8% to 10% business. You are looking, in terms of a return, at 10% on average over a long period.