One thing to keep in mind in analyzing the crack spread
relevant to earnings potential for refiners, is their ability
to switch from less profitable unleaded to more profitable
heating, diesel, and jet fuel.

Analysts that are using the standard 3+2=1 metric are
overlooking the switching ability by distillers and could
cause an earnings surprise to the up-side.

http://www.marketwatch.com/news/story/soaring-global-diesel-demand-burns/story.aspx?guid=%7B03493AE9-2748-4A5C-8EFF-89AC5A2B5693%7D&dist=msr_4