What does SN/GF-5 5W-30 mean?

[ZaneLee]

SN/GF-5 5W-30 means the following: 1. In SN, the 'S' stands for lubricating oil for gasoline engines, and 'N' represents the grade. According to the 26-letter sequence grading system, the current highest grade is N. In October 1990, ILSAC issued the GF-1 test specification for small car engine oils, establishing the GF-1, GF-2, GF-3, and GF-4 specifications for gasoline engine oils. In addition to meeting all the requirements of API SH, SJ, SL, and SM respectively, GF-1, GF-2, GF-3, and GF-4 must also pass the EC energy-saving requirements stipulated by ILSAC. 2. Simply put, the GF specification is the API specification plus energy efficiency. Introduced in 2010, GF-5 meets the SN requirements and is currently the highest grade for gasoline engine oils. In the engine oil 5W30, the '5' indicates the oil's low-temperature fluidity—the smaller the number, the lower the ambient temperature at which it can be used. It also indicates better engine protection during cold starts. The number 5 represents resistance to external low temperatures of -30°C. The '30' represents the kinematic viscosity standard at 100°C, which is 30. This number indicates the oil's high-temperature resistance—the higher the number, the better the oil's protective performance at high temperatures. 3. The 'W' stands for WINTER. The number before the 'W' indicates the oil's viscosity in low-temperature conditions—the smaller the number, the better the oil's low-temperature fluidity and the better the engine protection during cold starts. The number after the 'W' represents the oil's viscosity at 100°C—the higher the number, the higher the viscosity and the better the engine protection at high temperatures.