China's top quality watchdog and three other national departments released a joint guidance on promoting product quality of motor gasoline and diesel Wednesday, aiming to strengthen the quality supervision and promote domestic product oil development, China News Service reported.

Mei Jianhua, quality supervision director of the General Administration of Quality Supervision, Inspection and Quarantine, said China's overall oil quality is not high enough, and quality problems appeared repeatedly.

The guidance pointed that oil producers should improve the oil quality and follow the rule of market access.