18 September in


What is API SN PLUS?

API SN PLUS is an engine oil category requested by automobile engine manufacturers. This category is a supplementary bridge between the API SN / ILSAC GF-5 category and the new GF-6 category which is still in development. API SN PLUS addresses the additional performance demands required by auto makers to enhance the current GF-5 category specifically around low speedpre-ignition.

Why Did the API Decide to Release SN PLUS Ahead of the Impending GF-6 Update? 

API SN PLUS was proposed by ILSAC (International Lubricants Standardization and Approval Committee) on July 20, 2017 and reviewed further by the industry at the API LG Standards meeting on Aug 15, 2017. Because of delays in testing and development of ILSAC’s new GF-6 performance category, GM decided to move ahead with an improved engine oil specification to address Low Speed Pre-Ignition (LSPI), a phenomenon which had been discovered in Turbo charged, Direct Inject Gasoline (TGDI) engines. After developmental delays of their own, GM released the dexos1® Generation 2 specification in the third quarter of 2017. This next generation additive system showed improvements in fuel economy, engine deposit control, and introduced a new detergent system that drastically reduced the occurrence of LSPI events. This advanced development in the GM system left the other major OEM’s searching for a solution of their own to combat LSPI. These manufacturers immediately began implementation of a supplement to ILSAC GF-5 to protect turbo gasoline direct injected (TGDI) engines from catastrophic damage. This unprecedented request from OEMs highlights the severity of low speed pre-ignition (LSPI) and confirms the immediate need for higher performing lubricants to protect against internal engine damage.

What is Low Speed Pre-Ignition?

LSPI is the spontaneous ignition of the fuel/air mixture before the intended spark-triggered ignition event; similar in concept to pre-ignition or engine knock. Engine knock has been around since the beginning of internal combustion engines. LSPI, however, occurs specifically under low-speed, high-torque conditions, such as initial acceleration from a stoplight. This scenario can create conditions where the fuel/air mixture ignites too early in the combustion cycle, throwing off the engine’s timing.

Engineers suggest there are two major causes for LSPI: droplets of oil or fuel which are ejected from the piston crevice, and combustion chamber deposits. These droplets or deposits contain enough heat energy to ignite the air/fuel mixture before the intended ignition event. The exploding combustion charge then collides with the piston as it’s still moving up the cylinder, potentially damaging or destroying the piston, piston skirt or connecting rods. Engine using TDGI design are especially susceptible to LSPI as the increased cylinder pressure from turbocharging can create ideal conditions for pre-ignition if fuel/oil droplets or cylinder deposits are present.

How Does Engine Oil Reduce or Prevent LSPI?

The chemistry of an engine oil formulation can influence the risk of LSPI events. There are specific ingredients in engine oils which can promote LSPI events, while others can help reduce it. Engine oil formulation experts are faced with the difficult task of chemically addressing LSPI as well as all the other mandates and requirements of engine manufacturers. This challenge must be met with a holistic approach to oil chemistry – the complete formulation must work together harmoniously to maximize performance benefit and minimize negative trade off. Altogether, API SN PLUS technology delivers advanced oil performance. Benefits of this new technology compared to API SN category include:

  • Protection against LSPI events
  • Improved oxidation resistance
  • Improved turbocharger cleanliness
  • Improved wear resistance – especially in lower viscosity grades
  • Aeration control
  • Exhaust system component protection
  • Fuel economy gains
  • Overall service life

What is the Consequence for Not Using a SN PLUS Rated Oil Where Required?

LSPI can lead to significant damage to pistons and rods leading to very expensive repairs. LSPI events are known to happen at random and in series with each other giving little warning to the driver. API SN PLUS rated formulations ensure that modern engines get the protection they require to eliminate LSPI occurrences and operate in the highly efficient and performance oriented way in which they were designed.

KLONDIKE Transitions to SN PLUS

All KLONDIKE products that were designated as API SN transitioned to API SN PLUS fluid technology in the Summer of 2018. These KLONDIKE automotive engine oils include 10W-40 SN PLUS, 20W-50 SN PLUS, 5W-20 SN PLUS/GF-5 Synthetic Blend, 5W-30 SN PLUS/GF-5 Synthetic Blend, 10W-30 SN PLUS/GF-5 Synthetic Blend, 0W-20 SN PLUS/GF-5 dexos1® Full Synthetic, 5W-20 SN PLUS/GF-5 Full Synthetic, 5W-30 SN PLUS/GF-5 dexos1® Full Synthetic light duty motor oils.

KLONDIKE Lubricants Corporation is an independent Canadian company with oils and lubricants distribution facilities in:
Greater Vancouver, BC ● Edmonton, AB ● Winnipeg, MB ● Greater Toronto, ON ● Moncton, NB