Passenger Car Engine Oil Specifications



New engine oil standards are few and far between, so the imminent introduction of one of the most complex and most delayed specifications has recently found itself in the headlines fairly frequently.

The continued drive to improve fuel economy and reduce harmful emissions has placed greater demands on passenger car motor oils in recent years. Modern engines require higher levels of performance and far greater protection, fueling demand for improved lubricant and additive technology.

The incumbent ILSAC GF-5 standard, which was introduced in 2010and has been around far longer than anticipated, is soon to be replaced by its successor, ILSAC GF-6. With everything now finalized, the first licenses are due to emerge on May 1.

ILSAC GF-6 is an industry-led standard and its development has involved close cooperation between automakers, oil marketers and additive suppliers. It requires engine oils to pass seven engine tests-more than ever before.

GF-6 was first proposed in 2012, but its protracted development has been made all the more complicated by the unprecedented number of engine tests that have needed to be either updated or created from scratch. With engine technology constantly changing, up-to-date tests that represent real-world conditions are vital.

The latest iteration has seen four existing tests refreshed and three more introduced. ILSAC GF-6 not only looks to improve on its predecessor in terms of fuel economy, corrosion and wear protection, and sludge, varnish, oxidation and deposit control, it is also focused on low-speed pre-ignition and timing chain wear.

Just to add to the complexity, the new standard will be split into two sub-categories for the first time. ILSAC GF-6A is backward compatible as all previous categories have been. The SAE 0W-16 viscosity grade, however, will have its own GF-6B standard and is not backward compatible. Different symbols and labeling will help prevent confusion and misapplication, with the usual ILSAC Starburst logo being used for GF-6A and a newly introduced shield symbol used for GF-6B.

GF-6 is a natural evolution, but this was the perfect storm, said Kevin Ferrick, director of API product programs. A lot of tests had become outdated and had to either be replaced or new ones introduced, and development of some of the tests took longer than expected.

Theindustry uses engine and bench tests to measure lubricant performance, and periodically those engine tests need to be upgraded because the technology used may not be representative of the vehicles on the road, he explained. Its hard to continue to support tests that are based on older technology because the parts are simply not available anymore.

Id say this is a watershed moment for the industry, added Richard Dixon, technology manager at Shell. GF-6 was originally expected around 2015, but its taken considerably longer than expected. There are a lot of new tests in the category, and its taken time actually developing them. In previous categories, maybe a single engine test was changed, whereas this time there are many new ones.

Headlining the changes is a new engine test to help address low-speed pre-ignition, a phenomenon in gasoline direct-injection engines that sees uncontrolled combustion, which can cause considerable piston damage and lead to engine failure. One way of minimizing this risk is by pumping more fuel into the cylinder, but this is counterintuitive when trying to improve efficiency and reduce fuel consumption.

To meet the goal of achieving more miles per gallon, youve got to move to downsized turbocharged engines, and to have those you need to enable that technology with motor oil that addresses issues like low-speed pre-ignition, noted Dixon. Despite the delays, I think GF-6 will be well received as it is driving innovation, and the consumer will know that the product on the shelf will be good quality.

Frustrated by the delays, automakers approached API and asked for an interim classification to help address LSPI in the meantime.

They were getting concerned, said Ferrick. They needed oils in the market that could prevent the low-speed pre-ignition phenomenon at times occurring in small turbo-charged GDI engines. We introduced SN Plus to bridge the gap between API SN and the new standard.

With the delays experienced with GF-6, API formed the Lubricants Standards Development Review Group to consider ways to improve the standards development process.

Now that weve reached the end of the process, the outcome has not just been the new category itself, but there are also some healthy discussions about how we develop these in the future, said Dixon. Its become apparent that our industry needs to change the process, and it should be far quicker. We must identify the needs earlier and have the basic testing hardware ready. Hopefully we should have only one or two new tests next time.

OEMs have certainly had to step up a gear in recent decades to accommodate these new regulations aimed at improving the efficiency and fuel economy of the modern motor vehicle. With engine design changing significantly, the industry is under growing pressure to provide increasingly innovative lubricants and additives.

ILSACs GF-6 specification has been painstakingly developed to offer that protection and boost performance-and it should be well worth the wait, said Ferrick.

These standards arenot introduced too often, so this is quite an exciting period for the industry. It is definitely an improvement and is going to provide the protection needed by todays cars and trucks because the new tests are much more representative of the vehicles on the road, he said.

From the perspective of automakers, OEMs and marketers, they all have a duty to their customers to recommend or provide lubricants that protect vehicles.

In this Spotlight, Afton Chemical and Infineum discuss their preparations for the new standard.