Why GF-5 Engine Spec?

[M.D. Holloway]

From a trusted friend...

Why GF-5?
The Automotive Industry Speeds Towards GF-5
How will U.S. Government regulations drive the future of the automotive and lubricant industries?

Regulation drives vehicle design, which in turn drives new enabling technology.


By 2011 all new passenger vehicles manufactured in the United States will be required to meet new government regulations put in place to further improve fuel economy and reduce exhaust gas emissions.

Why create new regulations?
In the past 40 years, U.S. government regulations have brought about significant fuel economy and emission improvements through required mechanical and chemical component redesigns. While these regulations were successful, more progress is needed. The number of vehicles on the road continues to increase resulting in negative environmental impacts. And, the cost of fuel continues to increase resulting in amplified public demand for improved fuel economy. These factors accelerated the cycle of regulation and the performance upgrade of engine oils.



New vehicle designs will require new technologies from supporting industries
Automotive manufacturers will not be the only ones required to carry out the regulation-driven redesign. Supporting industries and technologies, such as oil marketers and lubricant additive industries, are currently working together to develop and define a new motor oil specification known as ILSAC GF-5. The GF-5 oils will be designed to improve the function and performance of the new engine and emission designs and help ensure compliance with the new government regulations.



GF-5 beyond the U.S.
The GF-5 specification will have a global impact. As with the previous GF-4 specification, Japan, Korea, and Canada are expected to adopt GF-5 immediately and global marketers of motor oils will add GF-5 to their requirements before 2011.



Consumers and GF-5
The transition to the new motor oils is seamless for owners. Their owners manual will tell them to use only motor oil carrying the API certification mark (Starburst). By the time 2011 vehicles hit the showroom floor, motor oils carrying the API certification mark will be ILSAC GF-5 quality.
Proposed improvements
Fuel efficiency and lower emissions are the main impetus behind the development of the ILSAC GF-5 specification.

Needs Statement
ILSAC GF-5 Needs Statement is approved by both ILSAC and OIL, as of the January 23, 2008 ILSAC/OIL meeting. The Needs Statement indicates the ILSAC GF-5 performance standard must provide improvements relative to ILSAC GF-4 in the following three categories:

Fuel economy and fuel economy retention
Engine oil robustness
Protection of emission control systems



Fuel economy and fuel economy retention

OEMs need improved fuel economy. However, the lubricant technology required to deliver the desired improvement cannot be defined at this time until test methods and limits are determined. The new Sequence VID test will be used to evaluate fuel economy and fuel economy retention.

ILSAC GF-5 oils will be required to deliver improved fuel economy when the oil is first put into the engine as well as after the oil has endured significant stress for many miles. ILSAC GF-5 oils may contain either organic or inorganic friction modifiers or possibly new, unique friction modifiers to meet the required improvements.

Protection of emission control systems
The ILSAC GF-4 phosphorous limits have not changed for ILSAC GF-5 and will likely remain at a maximum of 0.08% wt and a minimum of 0.06% wt.

The Emission System Compatibility Improvement Team, ESCIT, has recommended using the existing Sequence IIIG test @ 100 hours to best measure the phosphorous volatility and its impact on the emissions system. The need for this test is to define ZDP systems that demonstrate High Phosphorous Retention

Previously a chemical limit on the percent phosphorous was used to meet the need for improving Emission System Durability. However, for ILSAC GF-5, the Sequence IIIG engine test will measure the phosphorous retention. The phosphorous retention limit will be established around High Phosphorous Retention (HPR) ZDP.

Engine Oil Robustness
The following areas have been tentatively agreed upon to improve enigne oil robustness:

Flex Fuel Vehicle (FFV) emulsion and rust protection
The emulsion and rust protection specifically for vehicles using ethanol based fuels could require boosters or modifications to the additive technology.
Seal compatibility with a broader number of seal materials and types
How the broader coverage of seal materials will influence additive technology remains to be determined.
Additional Performance Requirements
Turbocharger Protection

Whether an improvement over GF-4 oils is required needs to be determined. The impact on additive technology cannot be answered until it is determined what specific characteristics need to be addressed.

Aeration

It has not been determined if air entrainment will be a part of ILSAC GF-5.

Protection for new technology engines

ILSAC GF-5 engine oils will be expected to provide protection for model year 2011 and beyond. This formulation must be beneficial to, and compatible with, any new innovations that occur in engine technology up to that point.

Protection in older engines
ILSAC GF-5 oils are expected to be backward compatible. Backward compatibility benefits sellers and buyers. It eliminates the need to carry separate products for older generation engines, simplifies the selection of the correct oil and decreases the likelihood that the incorrect oil will be used.

Determining performance to meet GF-5 specification


ILSAC GF-5 requires the development of a new test for measuring Fuel Economy and Fuel Economy Retention, the Sequence VID (pronounced "Six D"). The Sequence VID engine test will define minimum performance standards for fuel economy. The test development program includes a carefully designed testing matrix to define test precision.

Performance parameters for GF-5 are measured through a standardized set of engine, physical and chemical bench tests. To be licensed as an ILSAC GF-5 oil and carry the API starburst symbol, motor oils must first pass this battery of tests.


Engine tests
A series of laboratory engine tests ensure an oil meets all GF-5 performance requirements. Each engine test assesses one or more performance parameters, such as engine deposits, viscosity increase, valvetrain wear, fuel efficiency, or bearing corrosion.

Bench tests
Laboratory bench tests determine the lubricant's performance relative to corrosion, elastomer compatibility, oxidation stability, rust protection, emulsion stability, shear stability, and thermal stability.

Physical tests
A number of laboratory tests are run to determine the physical properties of the oil, such as viscosity, pour point, foaming tendency, and evaporation loss.

Chemical tests
Laboratory tests are also used to determine the chemical properties of engine oils. For example, additive elements, total base number (TBN), and sulfated ash. GF-5 oils must be tested for phosphorus, and sulfur content to determine if they are compatible with exhaust aftertreatment systems.