Spotlight on API SN Plus

Aug. 1, 2018
Now that turbocharged direct injection (TGDI) engines make up nearly 25 percent of U.S. vehicles sold, the American Petroleum Institute (API) has officially announced its new supplemental oil category API SN Plus to meet the demands of both consumers and original equipment manufacturers (OEMs) in protecting against low-speed pre-ignition (LSPI) in engines.

Now that turbocharged direct injection (TGDI) engines make up nearly 25 percent of U.S. vehicles sold, the American Petroleum Institute (API) has officially announced its new supplemental oil category API SN Plus to meet the demands of both consumers and original equipment manufacturers (OEMs) in protecting against low-speed pre-ignition (LSPI) in engines.

While oil brands, such as Mobil 1, have met the API SN Plus performance standard since 2010, many others will begin officially designating this on packaging beginning in 2018. The “Plus” designation is an improvement on API SN and specifically addresses LSPI as engineers work toward the approval of the long-delayed next generation of oil (ILSAC GF-6).

LSPI or “super knock” is an abnormal combustion event that is a major concern for modern TGDI engines. LSPI creates excessive pressure within the engine’s cylinders, which can cause permanent damage to cylinder walls, pistons, piston rings, connecting rods and spark plugs. The internal engine damage caused by LSPI could lead to catastrophic engine failure, which can take place when the air-fuel mixture ignites before the spark plug fires and typically occurs when an engine is under high load at low rpm (i.e., driving slowly and then rapidly accelerating).

Protecting against LSPI should be top-of-mind for all the automotive industry from auto manufacturers up to quick lube installers.

“Motor oil can play a significant role in the mitigation of LSPI, as the condition can be reduced by advanced technology in motor oil formulations,” said Ahmed Galaby, Automotive Discipline Technology lead at ExxonMobil. “Any oil on the shelf now should be designed to provide the performance desired by drivers and provide the protection for modern turbocharged engines, withstand stop-and-go traffic and every extreme condition and temperature condition that comes with modern driving.”

The first licensing date for API SN Plus was May 1, 2018, and installers will start seeing the API SN Plus donut symbol appear on motor oil bottles throughout 2018.