What do you mean when people say you are a black gas station?

Operating without a license, selling inferior oil.

Operating without a license, selling inferior oil, do not have to bear taxes and fees, the profits of illegal business mainly come from tax evasion, that is, black gas stations. There are great security risks in black gas stations because of poor equipment and facilities, unqualified operators, weak safety awareness and substandard fire-fighting equipment. Driven by interests, "black gas stations" sell mostly inferior oil, which is far below the national standard. Black gas stations are neither compliant nor legal, and there are great security risks.