Shell's mid-range products with synthetic motor oil technology. Shell Helix HX7 is an SN grade motor oil that has been approved by the American Petroleum Institute API for use not only in petrol, diesel and natural gas engines, but also for biodiesel and gasoline ethanol blends. As a semi-synthetic engine oil, the viscosity coefficient and low-temperature performance of Shell Helix HX7 are lower than those of Shell Extreme Clean Helix, of which 5W-40 is priced at 398 yuan for 4 liters in China, and the oil change mileage is 7500 kilometers.