What Does Engine Oil Grade Represent?
1 Answers
Engine oil grade meanings: "W" stands for Winter, indicating the oil's low-temperature fluidity, and the number following W represents kinematic viscosity. Taking "15W-40, 5W-40" as examples: 1. "W" stands for Winter, and the smaller the number before it, the better the oil's low-temperature fluidity, indicating a lower usable environmental temperature and better engine protection during cold starts. For example, 5W can withstand external temperatures as low as -30°C, while 20W can only withstand -15°C. 2. The number after W represents the oil's kinematic viscosity at 100°C, with higher values indicating higher viscosity. 40 means the kinematic viscosity standard at 100°C is between 12.5mm2/s and 16.3mm2/s.