Investors looking for the lowest cost refiner should look no further than Valero Energy (NYSE: VLO ). The company's operating structure provides a wide moat advantage that allows the company to produce strong financial results even inI am a Licensed Professional Engineer who works in the Nuclear Power industry. I use my professional working knowledge of the power/energy industries to aid in evaluating potential equities worthy of long-term investment. I invest in income producing equities and rental real es ...