Valero holds the status of America’s largest oil refiner. In 2012, it purchased Chevron’s Welsh refining operations, costing $730 million.  This is set to increase the company’s oil output 220,000 barrels a day. In addition, Valero is advancing production at some of its U.S. refineries, which is one of the main reason analysts anticipate double-digit earnings growth in the years ahead. While it reported quite a large loss in 2009, the following year Valero saw a profit.