There are over 60 companies refining oil into gasoline into this country. There are more than 100 domestic oil producers, a couple hundred importing oil and other petroleum products. Many of these are small independents. I don't understand the claim that the market is not competitive when these smaller operators have been in it for decades.
Exxon, BP, Shell, and a few other own the oil industry. This is, by definition, an oligopoly.
“I don’t understand the claim “
Willful ignorance