As engines in cars, trucks and SUVs have become more efficient in an effort to reduce emissions and increase fuel economy, the use of low viscosity motor oil has become an essential part of their operation. With advancements such as gasoline direct injected (GDI) and turbocharged direct injected (TGDI) engines came a request from automakers in 2012 to develop more robust engine oils that would be capable of meeting the needs of current and future gasoline engines.
“The development of ILSAC GF-6A, ILSAC GF-6B and API SP oils was completed over the course of seven years and the new oils became licensable under API’s engine oil program on May 1, 2020,” said Jeff Harmening, manager, EOLCS/DEF/MOM, American Petroleum Institute. “The new standards are the latest in a line of steadily more stringent performance specifications and replace ILSAC GF-5 and API SN standards.”
There were a number of challenges in launching the new standards that had to be considered. It is the first time the ILSAC specification has experienced a “split” ILSAC category and educating customers and consumers is important. Vehicle manufacturers will have to recommend very specific viscosities for different applications. They also may request even lighter viscosity grades be included in GF-6B in the future. This means that North American oil change locations will need to understand vehicle manufacturers recommendations and follow them carefully.
However, the biggest challenge was the need to develop new and replacement engine tests that support API standards. With changes in engine technology since the last specification in 2010, new tests were necessary to properly evaluate the new oils. Developing these tests for oil performance such as low-speed pre-ignition (LSPI) and chain wear protection requires collaboration and consensus between vehicle and engine manufacturers, oil marketers, additive companies and others to ensure the oils meet the needs of different engine technologies from a number of manufacturers.
“Seven new or replacement engine tests were developed, evaluated, and measured for precision and each test required a great deal of time and effort to ensure that it was fit for purpose,” said Dennis L. Bachelder, senior engineer, American Petroleum Institute. “The tests are designed to create extreme conditions so that new oils are robust enough to perform properly across an entire auto drain cycle which can be as high as 10,000 miles.”
A few examples of the rigorous process for testing include the following: The engine wear test is 200 hours involving 24,000 thirty- second cycles, with each cycle consisting of four stages: two steady-state stages with transition ramp stages between them. The LSPI test consists of four iterations. Each iteration is 175,000 ignition cycles from each cylinder with the first 170,000 valid cycles evaluated for the number of pre-ignition events.[i]
The official name of each of the seven new/updated tests is detailed below:[ii]
- Sequence IIIH Engine Test – Oxidation and deposits
- Measure lubricant thickening and piston deposits under high temperature conditions.
- Sequence IVB Engine Test – Wear
- Evaluate the effect of an automotive lubricant on tappet wear for engines with direct-acting overhead cam valvetrains.
- Sequence VH Engine Test – Sludge and varnish
- Evaluate the performance of a lubricant in controlling low temperature engine deposits under operating conditions deliberately selected to accelerate deposit formation.
- Sequence VIE Engine Test & Sequence VIF Engine Test – Fuel economy
- Provide a comparative fuel economy index (FEI) of the fuel-saving capabilities of automotive engine oils under repeatable laboratory conditions.
- Sequence VIII Engine Test – Corrosion
- Evaluate the performance of a lubricant in preventing copper/lead/tin bearing corrosion and measure viscous shear stability under high-temperature operating conditions using unleaded gasoline.
- Sequence IX Engine Test – Low-speed pre-ignition (LSPI)
- Evaluates the ability of a motor oil to mitigate pre-ignition in the combustion chambers of gasoline, turbocharged, direct injection (GTDI) engines under low-speed and high-load operating conditions.
- Sequence X Engine Test – Chain wear
- Evaluate a lubricant’s performance to protect against soot-induced timing chain wear experienced in modern gasoline direct-injection (GDI) style engines.
The auto industry, oil marketers, additive companies and others worked with API to develop these new performance standards, to meet the needs of current and future engines. GF-6A oils are backward compatible with GF-5 oils and older standards and in viscosities as low as 0W-20. GF-6B oils are backward compatible with 0W-16 oils meeting API SN performance and are intended for gasoline engines requiring 0W-16 oils. API SP is backward compatible with API SN oils and includes the new ILSAC specifications, but also covers engine oils that are intended for uses not included in the ILSAC specifications.
Knowing more about the strict process and testing that goes into new oil standards provides dealers, shops and quick lube operators with information they can offer to consumers about the high quality of the oils being poured into their engines.
[i] Test information provided by the Fuels and Lubricants Research Division at Southwest Research Institute.
[ii] Test information provided by the Fuels and Lubricants Research Division at Southwest Research Institute.