Why should PetroChina No.93 in Beijing Jetta and Langfang pay for oil?

It is estimated that there is something wrong with the quality of the oil. It is suggested that you find time to check and clean up the engine carbon deposit in the 4s shop, and do a vehicle inspection to avoid the poor quality of gasoline added elsewhere, and the carbon deposit inside the engine blocks the throttle or nozzle, resulting in waste engine oil. I suggest that when you refuel in other places, you must find a self-operated store of PetroChina or Sinopec to refuel. If you can go back to Beijing, try to go to other places to refuel as little as possible.