[thackney]

I may be wrong about this, but I imagine very little Canadian oil ends up as gasoline.

Sorry, but you are wrong. Essentially all of the Canadian feedstocks are used to make gasoline and diesel in US refineries.

The bitumen that is produced from the oil sands is typically first run through an upgrader before reaching a refinery. This adds cost but the lower price for bitumen offsets this making it a desirable feedstock.

http://www.oilsandsdiscovery.com/oil_sands_story/upgrade.html

Saudi Arabia typically provides a lighter grade of crude oil. However, all the crude produced in Saudi Arabia—except for that of the offshore Safaniya Field in the Persian Gulf—is "sour." This sulfur content requires removal in the refinery and also adds cost, but not as much as an upgrader.

http://www.saudiaramcoworld.com/issue/196001/sweetening.up.the.crude.htm

[Alberta's Child]

Well, there you go . . . I knew I pinged the right Freeper on that post. LOL.

I stand corrected!