Difference between API SN and SP?

[ArthurFitz]

The differences between API SN and SP engine oils are: 1. Different phosphorus content: The thickness of engine oil at certain temperatures, which can also be described as viscosity (phosphorus content), varies. SN oil has relatively lower phosphorus content, and when comparing the viscosity of SN and SP oils, SP has slightly higher viscosity values. 2. Different advantages: SP oil has stronger oil film formation than SN, providing better protective performance. Additionally, SP shows stable improvements over SN in terms of noise reduction, fuel economy, and acceleration performance. 3. Notes: For most vehicles, SM grade engine oil can generally meet daily usage requirements. M-grade engine oils offer better oxidation resistance, deposit control capability, and improved anti-wear protection, ensuring fuel efficiency and long-lasting performance. When purchasing engine oil, you can also refer to the vehicle's user manual to determine which lubrication standard should be followed. Simply choose engine oil from reputable manufacturers that meets the specified standards.