What is the difference between SP-grade and SN-grade engine oil?

[BenjaminAnn]

This classification comes from the American Petroleum Institute (API), where the preceding 'S' denotes oil specifically for gasoline engines, and the various letters following it represent oil standards. To date, there are 13 standards from SA to SP (SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN, SP). The further the letter is in the alphabet, the higher the working capability of the oil under that standard, and the more recent the year it was introduced. For example, the SP standard was introduced in 2020. So, what are the differences between SP-standard oil and SN? The biggest difference between them is that SP-standard oil adds the feature of resisting low-speed pre-ignition, which can prevent the common low-speed pre-ignition and timing chain wear in small direct-injection engines, providing better protection. Additionally, SP-standard oil contains less phosphorus than SN-grade oil, ensuring improved lubrication while significantly enhancing the fuel economy of the engine. In terms of other capabilities, SP-standard oil also shows comprehensive improvements over SN oil, such as in engine cleanliness, noise reduction, power responsiveness, wear protection, and oxidation stability. Now, do you understand the difference between SP-grade and SN-grade engine oil?

[SanAnthony]

I've driven various car models and have gained some experience with oil changes. The main difference between SP-grade and SN-grade oils lies in the API standards they correspond to: SN is the older version from around 2011, while SP is the newer upgrade post-2020. SP is more effective in reducing low-speed pre-ignition issues, especially in modern turbocharged engines or high-performance vehicles, preventing engine knocking and damage at low RPMs. It also enhances oxidation resistance, meaning less sludge buildup and longer engine life. I've noticed that SP can slightly improve fuel economy, giving a bit more mileage per gallon in daily driving, which saves some money on gas in the long run. For new car owners or those driving compact SUVs, I recommend going straight for SP instead of opting for cheaper SN in sensitive engines to avoid costly repairs down the line.

[StLaura]

Having worked in maintenance for over a decade, I frequently encounter engine oil issues. The difference between SP and SN lies in their API standard levels: SP is the newer specification, featuring additional protection against low-speed pre-ignition (LSPI) compared to SN, which reduces pre-ignition risks in turbocharged engines. SP also employs more advanced additive formulations that minimize sludge formation and enhance engine cleanliness. From practical observation, it further optimizes fuel efficiency, helping vehicle owners save 1-2% on fuel consumption. I've seen many customers using older SN-grade oil in newer vehicles, resulting in engine knocking—repair costs often exceeded the price difference of upgrading to premium oil. While SN may suffice for older naturally aspirated engines, SP is strongly recommended for modern vehicles. Always inspect oil samples regularly and consult the manual—don't cut corners.

[Shirley]

I usually drive to and from work, and the mechanic briefly explained the differences between SP and SN engine oils. SP is the newer version, meeting standards post-2020, and provides better engine protection against the 'knocking' sound during sudden acceleration (known as low-speed pre-ignition). SN is older, introduced in the 2010s, and offers slightly weaker protection. After trying SP, I felt the oil change interval was a bit longer, reducing trips to the repair shop. However, it's more expensive. If your car isn't new, SN is a cost-effective choice without issues. Always check your owner's manual for recommendations before choosing, and avoid unnecessary upgrades to save money.