U.S. refiners have returned from maintenance with a vengeance, processing more than 18 million barrels a day of crude and other oils for the first time in the week ended June 22. What does that mean for the markets? Gasoline stockpiles have increased 2.9 percent in June, the biggest gain for the month since 2009. There‚Äôs enough supply to cover 25.4 days of demand, almost a full day above the five-year average. Shrinking Margins The record runs are squeezing the once-mighty profit margins for refiners. The Nymex gasoline crack spread, a rough measure for how much refiners make from producing the motor fuel, sank more than 30 percent in June, the biggest drop for the month in a decade, helped by a tightening WTI-Brent spread. Out of Tune With gasoline the weakest relative to diesel seasonally in five […]