Shares of Frontier Oil Corp. also have soared. Valero attributed its stellar fourth-quarter results to its “superior leverage to sour crude discounts,” which were $10 per barrel cheaper ...

HOUSTON (Reuters) - U.S. sweet and sour oil differentials narrowed significantly this month, pricing data showed, as demand for higher sulfur crudes climbed from refineries and exporters while ...

NEW YORK/HOUSTON, May 12 (Reuters) - Sour crude oil supplies for U.S. Gulf Coast oil refiners will be squeezed in coming weeks, market participants said, as global demand rises following this ...

HOUSTON, June 20 (Reuters) - U.S. sweet and sour oil differentials narrowed significantly this month, pricing data showed, as demand for higher sulfur crudes climbed from refineries and exporters ...