Know API SN PLUS
The API Association published the relevant specifications for SN PLUS on May 1, 2018: API SN PLUS is a new oil specification developed for turbocharged engines and is being developed in response to automotive manufacturers' requirements for preventing low speed pre-ignition (LSPI) oils. LSPI is an engine condition known to occur in turbocharged gasoline direct injection (TGDI) engines that can be mitigated by changing the oil formulation. The API SN PLUS engine oil specification is designed to complement the API SN and ILSAC GF-5 and is designed for addressing the increasing impact of low speed pre-ignition in turbocharged gasoline direct injection (TGDI) engines. In these smaller TGDI engines, high pressure and direct fuel injection from the turbocharger injecting into the combustion chamber make them susceptible to the phenomena known as low speed pre-ignition or LSPI. Although the mechanism of LSPI is not fully understood, studies have shown that oil properties may be a contributing factor. Automakers can mitigate LSPI by adjusting engine operating conditions. However, the action will inhibit some efficient engine operating conditions. As automakers become more concerned about LSPI, the urgent need to replenish oil specifications has become apparent. This new supplemental specification is called API SN PLUS.