A new oil service category, SN Plus, has been approved by the American Petroleum Institute (API) for release Summer 2018 and Old World Industries will be ready. API began licensing API SN Plus motor oils May 1, 2018.
API SN Plus is an interim oil service category developed specifically to address immediate OEM warranty concerns from increasing Low-Speed Pre-Ignition (LSPI) events in turbocharged and downsized Gasoline Direct Injection (GDI) engines. The GDI engine market for automotive is expected to grow at a compound annual growth rate of ~9.9 percent from 2017 to 2025.[1]
All automobile gasoline engines operate on a carefully timed 4-stoke cycle process in which combustion is timed by controlled sparked ignition. It is paramount that fuel combustion occurs at the appropriate time or catastrophic engine failure can occur. Compared to port fuel injected or carbureted engines, GDI engines produce higher compression to increase fuel combustion efficiency delivering better fuel economy and more power/torque in a smaller displacement. Sounds great! However, GDI engine compression pushes the limit of prematurely auto-igniting the fuel. The frequency of these events increases with time as combustion deposits contribute to the pre-ignition phenomenon. Unfortunately, LSPI events cannot be predicted and corrected by adjusting spark timing and repeated LSPI events are reportedly increasing warranty claims.
What is the difference between API SN and SN Plus engine oil believed to mitigate LSPI? Certain engine oil additives used for decades are now thought to contribute to LSPI events in GDI engines because engine oil slipping past the piston rings into the combustion chamber mixes oil additives with the fuel. API SN Plus approved motor oils are formulated to deliver the same, or better, engine lubrication protection as API SN motor oils by using less of the suspect additives and increasing other, more expensive, additives thought to lower engine oil’s LSPI contribution. This formulary change will increase cost impacting pricing.
Why SN Plus? Why not SO? Normally, API parallels ILSAC, API’s European counterpart, in creating the next API oil service category for gasoline engines but ILSAC has experienced many challenges impeding the release of ILSAC GF-6. API decided to move ahead with a “bridge” between major oil service categories upon urgent request of North American OEMs needing this change now for their small GDI engine class.
PEAK® Dexos1™ Gen 2 Full Synthetic Motor Oil’s already exceeds API’s SN Plus oil service category requirements and will soon bare API’s SN Plus Resource Conserving donut. Additionally, All of Peak’s low viscosity multi-grade passenger car engine oils will update to API’s SN Plus oil service category in 2018. Old World Industries is targeting July 1st to launch API SN Plus 0W-xx, 5W-xx and 10W-30 viscosity grade passenger car engine oils. Packaged goods will update on rolling change over the second half 2018 into 2019.
[1] Source: Gasoline Direct Injection Systems (GDI) Market to surpass $10 Bn by 2024, Sep. 28, 2017