Got used to ILSAC GF-5? Well, get ready for ILSAC GF-6

One of the ways that OEMs will be trying to meet the new fuel efficiency standards and emissions targets is moving to engines with smaller displacements and direct gasoline injection engines.

In August of 2012, the Obama Administration in the United States finalized new fuel economy standards that will have vehicles and light-duty trucks achieving the equivalent of 54.5 mpg (87.71 km) by model year 2025, which is nearly double the fuel-efficiency of many of today’s vehicles.

In order to meet that target, vehicle makers are going to have to make significant improvements to engine designs and motor oils will need to be formulated to operate successfully in these new engines. These new engines will put new strains on what the motor oils will have to accomplish, particularly in the areas of wear protection and deposit control, as direct gasoline injection engines, as an example, will operate under very high tolerances and will not take kindly to oils that cannot protect vital components from friction and contamination.

That is where ILSAC GF-6 comes into play, as the OEM engine and car makers have identified several key areas that need to be addressed by ILSAC GF-6. Along with improving fuel economy, ILSAC GF-6 will also need to focus on protecting against engine oil-caused low-speed pre-ignition, as new engines will have smaller displacements and may be turbo-boosted which can make them prone to low-speed pre-ignition issues. Another area is better protection for idle stop engines and for various components such as timing chains and valve train. There is also a push for formulations to avoid oil aeration over the oil change interval.

“Compared to the time 20 years ago, modern engine technology is very efficient,” says Oliver Kuhn, research and development department with Liqui Moly. “The price for this: it is not very tolerant toward contaminations anymore. Any kinds of deposits hamper the combustion, resulting in higher fuel consumption and increased build-up of additional desists. GF-6 compliant motor oil will have to take more care of that issue. It needs to be formulated in a way that it does not contribute to contaminates when burned in the engine; and it has to have the cleaning capabilities necessary to remove deposits.”

Blenders of motor oils and engine test engineers are working right now to finalize the new GF-6 standard and put it up against a new set of engine wear and deposit tests in order to meet those mileage and emissions standards.

New Engine Tests

“At the moment, most of the work [for GF-6] is engaged in developing new engine tests for the GF-6 category,” says Dr. Robert Sutherland, Pennzoil technology manager. “The strongest driver is that the parts are out of production in the current suite of engine tests.”

Sutherland adds the new suite Sequence Tests will be addressing specific engine and fuel efficiency requirements that GF-6 will have to meet, covering normal commuting conditions and those unique to the kinds of engine that will start appearing in the next few years.

Some of those Sequence tests will include a Sequence VH that will look at sludge and varnish build-up. This test will look at how well GF-6 oils prevent the formation of these deposits that often occur when vehicles are used in city commuting. The Sequence IVB is a wear test and will look at how well the oils stop camshaft lobe wear, simulating light city driving and will replace the earlier GF-5 test and hardware. The Sequence IIIH test is designed to put the GF-6 oil through its paces in conditions simulating high-speed driving, such as you might see during highway commutes. This test is to examine if the new GF-6 can resist thickening and stop deposits forming on the pistons when the oil and pistons work under high temperatures.

“The Sequence VID test will be replaced by a Sequence VIE and this is a General Motors test and it will require the industry to raise the level of fuel economy derived from the oil,” Dr. Sutherland says. “The fuel economy the oil delivers and the cleanliness the oil will maintain are both important for fuel economy. If you let the engine accumulate deposits, it will have an impact on the engine systems and diminish fuel economy.”

Two GF-6 Motor Oils?

One of the ways that OEMs will be trying to meet the new fuel efficiency standards and emissions targets is moving to engines with smaller displacements and direct gasoline injection engines.

Thom Smith, vice-president, Branded Lubricant Technology with Ashland Consumer Markets (Valvoline), says some of the new engine Sequence tests will look specifically at making sure GF-6 operates successfully with direct gasoline injection engines and these smaller engines.

“There will be a new wear test based on a Nissan engine and another will be based on a Toyota engine,” he says. “One of the concerns with direct injection gasoline engines is the type of soot that can be produced in the engine and this can lead to wear of the timing chain. We are also going to have a pre-ignition test and a new fuel economy test which is going to have more severe requirements.”

Probably one of the most interesting debates around GF-6 is the possibility of there being two GF-6 specifications, one specifically blended to meet the viscosity requirements of small displacement engines. In fact, some OEM vehicle makers are already looking to have their new small displacement engines work with SAE 5W-30 and even 0W-20 oil in order to reach the new fuel efficiency requirements while still providing needed wear protection for critical engine components.

“There is a thin line between fuel economy and wear and tear,” says Liqui Moly’s Kuhn. “An oil [that is] too thin is not able to lubricate properly anymore, so a further viscosity decrease is not an option for older engines. This is why there will be two types of GF-6 – for the first time, there are GF subcategories. GF-6A is the more traditional specification and backwards compatible with GF-5 and its predecessors. GF-6B is the more innovative specification with reduced viscosity. GF-6B comes along with the new SAE16 viscosity category which is ‘below’ the SAE20. This is a benefit for upcoming generations of engines, but may be harmful for older engines.”

In order to prevent consumer confusion, Dr. Sutherland says a new symbol will likely be created to clearly mark the new viscosity grades so as to make sure technicians and consumers know which oil to use with their vehicle.

Everyone mentioned that regardless of what is finally decided, it will be critical to make sure consumers take a close look at their vehicle owner’s manual to ensure that the right oils are used.