Will GF-4 Oils Play Nice With Others?


HOUSTON — With the single exception of backward compatibility, automakers have basically completed the “needs” statement defining what specific improvements are necessary for GF-4, the next gasoline engine oil category. Four substantive issues are now front and center for the automotive and engine oil industries: needs, tests, timing, and backward compatibility.

The “needs” statement is the automakers’ statement of why a new engine oil category is needed, and what specific improvements are expected over today’s GF-3/API SL engine oils. According to the “needs” statement issued by ILSAC, which represents U.S. and Japanese automakers, GF-4 must include the following improvements:

1) A reduction of the oil’s effect on catalyst and emission system components, to meet federal regulations for the 2004 model year vehicles. Tightened emission standards will require that catalysts be effective up to 120,000 miles, but current oils (GF-3 and API SL) contain phosphorus levels that the auto industry believes will shorten catalyst life.

2) Better low-temperature rheological properties of used oil, to reduce the possibility of field failures due to inadequate low-temperature pumpability.

3) An increase in fuel economy and fuel-economy retention and durability.

4) Improved robustness during high-temperature/high-load operations, to improve piston ring belt cleanliness and control of nitration and oxidation.

GF-4’s test battery will include two new engine sequence tests, as the API Lubricants Committee heard when it met here last Thursday. Both tests appear to be on a very tight, but doable, trajectory.

First, the Ford-sponsored Sequence VIC (“six C”) test is designed to measure the fuel economy benefits of an engine oil after aging. The “C” version of this test is basically an extension of the “B” version, a current requirement of GF-3 engine oils. API’s Lubricants Committee last week heard that Ford is nearing a decision on how to proceed with this test.

Second, the General Motors-sponsored Sequence IIIG measures wear and oxidation. GM has presented data suggesting appropriate wear severity has been achieved on this test when using phosphated camshafts. While it’s willing to review additional IIIG development data, in terms of hardware and operation, GM now considers the IIIG ready for matrix testing.

Details for the Sequence IIIG matrix, including financing, are being worked out and testing is expected to begin on Aug. 1. Lubrizol’s Don Marn will lead GF-4’s Matrix Design Task Force and John Zalar, director of ASTM’s Test Monitoring Center, will act as matrix manager, keeping track of and reporting on its progress.

A timeline for implementation of GF-4 has not been agreed on, but ILSAC’s proposed first commercial use in spring 2003, with mandatory use in late fall 2003, has not changed. API’s licensing schedule, however, has not been determined. The usual pattern is for API licensing to begin either nine or 12 months after final approval of an engine oil. The auto industry now wants API licensing to commence with initial commercialization.

Let’s not mince words. Backward compatibility is the single, overarching issue facing GF-4, depicted by ILSAC as a “category breaker.” If GF-4 is not backward compatible, vehicles produced prior to 2004 would need a different oil (GF-3, for example) to lubricate them.

A marketplace where GF-3 or API Service Category (SL or SJ) oils would lubricate pre-2004 vehicles and GF-4 oils would lubricate 2004-and-later vehicles presents, to put it mildly, problems in consumer education, in licensing and “starburst” display, in warranty concerns, and for quick-lube and other retail operations.

The auto industry is adamant on the issue of multiple categories as the following statement, presented to API’s Lubricants Committee last Thursday, indicates: “[Original equipment manufacturers] will not be willing to incur the risks of using GF-4 oils for certification if GF-3 and other similar categories exist in the market.”

The phrase “and other similar categories” suggests that when GF-4 arrives, the auto industry would like all existing API “S” categories to be declared obsolete because these categories have phosphorus levels above 0.05 mass percent and could be used in 2004 vehicles.

Further, ILSAC “believes that the market segmenting that currently exists between API ‘S’ categories and ‘Starburst’ oil is detrimental.”

Wear is the core of the backward compatibility issue. If phosphorus is halved (from 0.10 mass percent to 0.05), oil formulators’ ability to use the inexpensive and familiar antiwear agent zinc dialkyldithiophosphate (ZDDP) is reduced. Other antiwear elements are in the armamentarium of additive companies but they are more expensive.

This matter has particularly engaged the attention of Ford Motor Co. For some time, it has been testing prototype GF-4 oils with phosphorus levels at 0.05 mass percent, as supplied by four major additive companies.

Ford’s Mike Riley reported on its testing progress on May 17 to the ILSAC/OIL task force, chaired by GM’s Bob Olree, and on May 23 to API’s Lubricants Committee, chaired by Valvoline’s Fran Lockwood. Riley explained that his company had major fleet tests under way to evaluate engine systems and basic functions, and added, “So we piggybacked our lubricant tests onto these major test programs. Twenty-nine vehicles are being evaluated with six different engines under varying operating conditions (city/highway, taxi, delivery, shuttle) up to 150,000 miles. These engines are equipped with the following valvetrains: 1) Overhead cam direct acting mechanical buckets, 2) Overhead cam end-pivot finger followers and 3) Overhead cam-in-block pushrod.

“Thirty-six more vehicles are scheduled to start mileage accumulation in the next few months resulting in prototype GF-4 oils being tested in 11 different Ford engines,” Riley added. “Drain intervals were extended up to 12,500 miles to challenge the oils to perform under severe operating conditions. Emissions are being evaluated to determine the effect of lower phosphorus. Total mileage accumulation to date on prototype GF-4 oils is about 1.73 million.”

Riley presented technical data and summarized the results as follows: “Used-oil analyses from all fleet evaluations indicate prototype GF-4 oils provide equivalent performance compared to GF-3 oils. Iron wear metals are usually less than 100 ppm, which is considered acceptable. Other wear metals were at acceptable levels and also indicated equivalent performance.

“Further, statistical analysis of pre- and post-test engine inspections of three Windstar 3.0-liter Vulcan taxis indicate their wear performance with GF-4 oils was equivalent to nine Windstar 3.0-liter taxis using two different GF-3 oils after 90,000 miles. Sludge and varnish were equivalent also.”

Further data from other fleets will be provided as it becomes available, Riley indicated.

API’s Lubricants Committee expressed appreciation for Ford’s data presentation. In addition, DaimlerChrysler will shortly present its GF-4 test data to the ILSAC/OIL Task Force.

Subsequent to the presentations, an ILSAC spokesman told Lube Report, “Since the wear requirements of the new Sequence IIIG test are tougher than the Sequence IIIF for GF-3 that it replaces, GF-4 oils should provide the same or better wear protection than GF-3 oils.

“In addition, the IIIG 3.8-liter V6 engine uses hardware similar to that used in some of the older engines most sensitive to wear in the field. ILSAC believes, therefore, that backward compatibility should not be an issue.”

A clear way forward to resolve the issue of GF-4 backward compatibility is not yet in view. Nor is it understood how the lubrication requirements of vehicle imports to the United States (for example, 205,000 Mercedes-Benzes in 2000) will be met.

These are thorny issues but the accumulation of data, such as that presented last week by Ford, has begun to lay a foundation for resolution. And there is a sincere desire by each participating industry — oil, chemical additives and auto — to reach an acceptable resolution.

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