In September, China Great Wall lubricating oil manufacturing Co. developed a new product for gaseous fuel engines, CNG engine lubricating oil and LPG engine lubricating oil. The products fill in the gaps in the fields of China's lubricating industry. It has obtained the relevant certificate and being produced in batches. Because of less toxic substance in tail gas, gaseous fuel has become the ideal fuel for buses and taxis. CNG and LPG are most common used gaseous fuel.