GF-5 Performance Requirements
Proposed improvements extend from spark plug to tail pipe
Fuel efficiency and lower emissions are the main impetus behind the development of the ILSAC GF-5 specification. But as the chart below shows, new requirements will improve passenger vehicle performance from spark plug to tail pipe.
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 engine 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.
