Which is better, SP or SN grade engine oil?

[OValentina]

Whether it is SP or SN grade engine oil, they are both API certified standards. Although the best choice is the oil that best suits your vehicle, SN grade oil is the latest standard introduced. Theoretically, SP grade oil is better than SN grade oil, with superior performance. Here is some information about API: 1. API grades are as follows: There are currently 13 types of S-series engine oils, namely SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN, and SP. According to the alphabetical order, the oil represented by a later letter is superior to that represented by an earlier letter. 2. API certification standards: API is the abbreviation for the American Petroleum Institute, which is responsible for setting standards. Engine oils that meet API certification standards will bear the API certification mark.

[LaRyan]

Last time during maintenance, I was studying the oil can and indeed, the SP grade is a higher tier than SN. You see, SP is the new standard introduced in 2020, essentially a comprehensive upgrade. It specifically addresses the low-speed pre-ignition issue that small-displacement turbocharged engines fear the most, effectively suppressing that 'click-click' knocking sound. It also enhances protection for the timing chain, with lab data showing a 30% improvement in oxidation resistance. However, my old Camry runs just fine with SN-grade mineral oil—the key is to follow the manual's requirements. For new cars or engines with a 'T' (turbo), going straight for SP is definitely the right move.

[EvaMarie]

After a decade in auto repair, I've seen too many cylinder scoring cases. Engine oil standards are no myth. SP outperforms SN in three key areas: doubled anti-wear additives that can protect today's precise direct injection engines; upgraded detergent formulas reduce sludge buildup by half; and specially enhanced high-temperature deposit control. During one teardown comparison, camshafts using SP oil looked shiny like new, while SN showed visible wear marks. However, SN is perfectly adequate for naturally aspirated engines - I still keep several barrels of SN in stock for my regular customers.

[TannerDella]

Don't be fooled by the alphabetical order! Although 'P' comes after 'N' following 'S', it's actually a leapfrog upgrade. It's like phones transitioning from 4G to 5G - the SP standard specifically addresses pain points of modern engines. The most crucial improvement is the addition of 'Low-Speed Pre-Ignition (LSPI) resistance' formulation, which is particularly essential for today's 1.5T small-displacement turbocharged engines. It also enhances turbocharger protection, with data showing a 35% reduction in turbo failure rates. However, older vehicles don't need such advanced oil - my dad's 2006 Accord runs just fine with SN-grade semi-synthetic oil, steady as a rock.

[OliviaLynn]

I was just educated about this during my recent oil change. The SP standard primarily targets engines developed after 2017, especially those compliant with China VI emission standards. Tests prove it can last 5,000 km longer without performance degradation, with a 20% improvement in high-temperature shear resistance. Interestingly, SP-grade oils generally contain more molybdenum, forming a more durable protective film on metal surfaces. However, the price difference is significant—SP costs 10-15 RMB more per liter than SN within the same brand. My advice: choose SP for cars under three years old, while SN is more cost-effective for vehicles over six years—just ensure the viscosity meets the manual's requirements.

[LolaAnn]

There's a lot to decipher in those letters on the oil can. The biggest improvement of SP over SN is solving the super knock issue in direct injection engines, and it's more compatible with models equipped with GPF particulate filters. The new standard requires lower phosphorus content to avoid poisoning the three-way catalyst and adds seal compatibility tests. However, there's no need to mythologize SP—I've measured two oils from the same brand, and their 100°C kinematic viscosity was basically identical. The key is to look for certification marks. SP is preferable if available, but stock SN oils that meet the ILSAC GF-5 standard are still perfectly safe to use.