Is 5W30 Fully Synthetic Engine Oil?
1 Answers
5W30 engine oil can be fully synthetic, but the viscosity grade is shared by oils of different qualities. For example, the 5W30 variants of Mobil Super, Shell HX6, and Castrol GTX are semi-synthetic oils; while Shell HX5, Shell HX3, and Total Quartz 3000's 5W30 are mineral oils. Relevant explanations are as follows: Quality Grade Classification: Engine oils can be categorized into fully synthetic, semi-synthetic, and mineral oils based on quality grades. Fully synthetic oil is the highest quality, followed by semi-synthetic, with mineral oil being the lowest. Standard Four-Season Engine Oil Viscosity Grades: 5W20, 5W30, 5W40, 5W50, 10W20, 10W30, 10W40, 10W50, 15W20, 15W30, 15W40, 15W50, 20W20, 20W30, 20W40, 20W50. Meaning of 'W': 'W' stands for Winter. The number before 'W' indicates the oil's fluidity at low temperatures—the smaller the number, the better the fluidity. Conversely, the number after 'W' represents the oil's viscosity grade at high temperatures—the larger the number, the higher the viscosity, providing better engine protection.