What Does the Oil Model Number Mean?

[VictoriaDella]

The oil model number indicates viscosity and quality, which includes 0w40, 5w30, 5w40, 10w40, 15w40, 20w50. Taking 0w40 as an example: 1. 'w' stands for winter usability; 2. '5' means the oil can flow at -30°C, where a smaller number indicates suitability for lower temperatures and better cold-start protection; 3. '40' represents the kinematic viscosity at 100°C, with higher numbers indicating higher viscosity. The selection of oil model depends on: the severity of the internal combustion engine's working conditions, oil capacity vs. compression ratio, and fuel properties.