According to the International Energy Agency's latest monthly report, refining margins surged to four-year highs in early July as product markets tightened even while crude prices tumbled.

Renewed U.S.-Iran strikes have revived the Middle East risk premium, lifting Brent above $76 as traffic through the Strait of Hormuz slows and supply disruption fears return.

Prices at the pump sank following a June ceasefire. But renewed conflict in the Middle East and other factors are driving fuel costs back up.