What does 20w50 mean for engine oil?

[BellaLee]

Engine oil 20W-50 indicates that the fluidity is too low and the viscosity is too high, suitable for use in high temperatures. The number 20 represents the minimum temperature, W stands for winter, and 50 represents the viscosity. Here is a detailed introduction about engine oil: 1. "W" stands for winter. The smaller the number before it, the better the low-temperature fluidity of the oil, indicating a lower usable environmental temperature and better protection for the engine during cold starts. 2. The number after "W" (after the hyphen) is an indicator of the oil's high-temperature resistance. The larger the number, the better the oil's protective performance under high temperatures. 3. 20w is most suitable for external summer use and can be used at temperatures not lower than -15 degrees Celsius.