Since the end of September, Brent Crude has been sliding — down to the $84-a-barrel range, more than a 10% decline in just over a week. This is also playing out at the pump, with gas down about eight cents a gallon in the last week.

They’re making less on crude, more on refining it.

Dated Brent, used to set the price of most of the world’s oil, will include supplies from Texas for the first time.