How often should Shell Helix Ultra fully synthetic engine oil be changed?

[OEverly]

Shell Helix HX7 should be changed every 7,500 kilometers or every 7-8 months. 1. Shell Helix HX7, as a semi-synthetic engine oil, can be changed every 7,500 kilometers or every 7-8 months. Shell Helix HX7 Plus should be changed every 10,000 kilometers or once a year. 2. HX7 Plus or Shell Helix Ultra Blue, both of which are fully synthetic engine oils, can be changed every 10,000 kilometers or once a year. Additional information is as follows: 1. Fully synthetic engine oil is a high-grade oil product among engine oils. 2. It is derived from ethylene and propylene dispersed from natural gas or crude oil gas, which are then processed through complex chemical reactions such as polymerization and catalysis to form a lubricating fluid composed of large molecules. 3. Essentially, it uses the better components of crude oil, undergoes chemical reactions, and achieves the desired molecular form under human control. Fully synthetic oil molecules are neatly arranged, naturally possessing strong resistance to external variables. Therefore, it has better physical properties, with significantly superior heat stability, oxidation resistance, and viscosity change resistance compared to mineral oil and semi-synthetic oil.