Is the impact significant if Civic uses 5W40 engine oil?
1 Answers
Honda Civic cars are not recommended to use 5W40 engine oil due to its higher viscosity. Here are the extended details: 1. Both 5W30 and 5W40 are all-season engine oils, where 5W indicates they share the same low-temperature starting performance. The main difference lies in the numbers 30 and 40, which represent the oil's fluidity at 100°C. According to the engine oil grading rules, the larger the number after W, the poorer the fluidity at 100°C. 2. Engine oils are categorized into mineral oil, semi-synthetic oil, and full-synthetic oil based on their base oil composition, with performance increasing in that order. Full-synthetic oil is recommended as it provides better engine protection and significantly delays the degradation of oil performance and engine power.