ILSAC requests API to develop a supplement to API SP

A group of automakers, which includes Ford Motor, General Motors, Stellantis and Toyota Motor, has requested that the American Petroleum Institute (API) develop a supplement to the existing API SP engine oil specification. 

API SP is the latest API gasoline engine oil standard. Introduced in May 2020, API SP was designed to provide protection against low-speed pre-ignition (LSPI), timing chain wear protection, improved high temperature deposit protection for pistons and turbochargers, and more stringent sludge and varnish control. API SP with Resource Conserving matches ILSAC GF-6A by combining API SP performance with improved fuel economy, emission control system protection and protection of engines operating on ethanol-containing fuels up to E85.

The proposed supplement to API SP would include an aged oil LSPI protection requirement. 

Presently, the API SN PLUS and API SP/ILSAC GF-6 specifications address the lubricant’s fresh oil LSPI performance in a turbocharged gasoline direct injection (GDI) engine. 

“Further protection is now necessary to prevent equipment failure which may be connected to a degradation in the LSPI protection of the lubricant over its standard oil drain interval,” wrote Michael Deegan of Ford Motor Co. Deegan is the ILSAC/Alliance Lubricant Working Group chair. 

The Sequence IX test is a fresh oil test. Thus, the API SN PLUS/SP Sequence IX limits do not confirm that the LSPI protection is retained as the oil ages in the field, he said.

To address this need, Ford has sponsored the work of an ASTM task force. The group took the oils from SAE publications 2018-01-1676 and 03-11-01-0002, which showed an increase in LSPI activity with oil aging, developed an aging test procedure using the Sequence X engine and evaluated the LSPI protection of these oils in the Sequence IX test. The data generated by the Task Force showed that the oils can be aged to simulate field conditions, and that their Sequence IX LSPI activity was higher than the fresh oils. 

Because of the task force work, ILSAC is requesting that the API Lubricants Group consider the  request for a supplement to the existing API SP specification to further protect the turbocharged GDI  engines for which the SN PLUS, SP (and ILSAC GF-6) categories were originally developed. 

The plan is to develop the Sequence X oil aging and Sequence IX aged oil as ASTM standards. To achieve this, a precision matrix will need to be run on both new tests. Deegan said the group is now seeking the funding to do this. 

The API Lubricants Group has scheduled a meeting on September 2 to discuss the request from Ford/ILSAC.