Ben Weber of Southwest Research Institute, chair of an ASTM section on passenger car engine oils,summarized the status of proposed engine sequence tests for the anticipated five-year life of the category, from 2009 to 2014.

Sequence Test Status
Five sequence tests are currently planned for GF-5:

1) The Sequence VIII, which measures bearing weight loss, had been the subject of possible elimination, to be replaced with the Cummins Corrosion Bench Test. The committee decided that the Cummins test was not a suitable replacement, so the Sequence VIII will be a GF-5 requirement.

Weber reported that the existing Sequence VIII engine parts inventory could last until 2015 at the average usage of 10 tests per month. He also reported that lead from existing bearings in storage continues to leach into the storage oil; the Central Parts Distributor has been working with a manufacturer to procure a new batch of bearings and resolve this problem.

2) For the Sequence IVA test, which measures camshaft lobe wear, Weber reported that there are options available for continuing this test, whether it includes upfront, long-term purchases by the lab or the Central Parts Distributor, or continued annual buys [of test engine parts] directly from Nissan.

3) The Sequence IIIG, which measures weighted piston deposits, used oil low-temperature viscosity and viscosity increase, faces no issues during GF-4, the current engine oil spec. However, a new IIIH test will be needed for GF-5.

4) The Sequence VG, which measures low-temperature sludge, currently uses an out-of-production 1993 Ford 4.6-liter engine and hardware, with parts stockpiled through GF-4s anticipated demise in 2009. The same test, but with some new hardware (cylinder heads and intake manifolds) will be required for GF-5.

5) The Sequence VIB, which measures engine oils contribution to fuel economy, also uses the 1993 Ford 4.6-liter engine and hardware. Weber reported that the test, with some hardware changes to come, is suitable for all of GF-4. A new test will be required for GF-5.

New Test for Fuel Economy
Vehicle manufacturers have insisted for at least a decade that new categories for gasoline engine oils must have a demonstrable fuel economy component. They assert that this requirement is a valuable resource conservation measure for the country. In addition, engine oil fuel economy helps automakers meet their mandated corporate average fuel economy (CAF) requirements.

Last October, ILSAC (that is, U.S. and Japanese automakers) unanimously agreed that the current Sequence VIB test, which measures engine oil fuel economy, had to be replaced for GF-5.

In January a 10-member task force was established, with McMillan as chair. Its objectives included agreeing on testing procedures to be used in generating correlation data, overseeing testing and producing a report on testing results, providing input on engines and the oil matrix to be included in the testing program, and collection and analyzing data on proposed engine or bench tests.

The task force presently believes that either a bench test or engine dynamometer could be considered to measure engine oil fuel economy in GF-5. A bench test would be substantially less costly than an engine test.

However, ILSAC believes strongly that a bench test alone is not suitable for predicting engine oil fuel-efficiency improvements, because of carryover, contamination and used oil effects, among other reasons. Therefore, while a bench test is a consideration, ILSAC has declared that a fuel-efficiency test for GF-5 must include an engine dynamometer test – that is, an engine test.

Michael McMillan of General Motors reported to the ILSAC/Oil meeting that the current test doesnt measure benefits of friction modifiers seen in many other engines, and it has exhibited precision and pass-rate difficulties. He added that there are indications of broad industry support (OEMs, oil and additive companies) for developing a test to replace the Sequence VIB.

Both General Motors and Southwest Research submitted proposals for generating preliminary data to serve as a basis for developing the new fuel-economy test(s).

McMillan said the next step is for ASTM to establish a task force to develop the replacement test(s). Its goal, he said, should be to solicit test development proposals during the second half of 2005 and complete test development during 2006.

Accept a Non-ASTM Test?
Japanese automakers have indicated concern with the ability of todays GF-4 oils to lubricate timing chains effectively. Several Japanese companies have developed chain-wear tests and are using them in Japan. Adapting one of these tests for GF-5 could reduce duplication and save money.

(A precedent exists for accepting a non-ASTM-originated test for U.S. engine oils. The Sequence IVA was originally developed by Nissan; however considerable work was required to bring the Nissan test into an ASTM standard.)

The American Chemistry Councils acceptance of an engine sequence test into its Code of Practice is a core requirement for the tests use in licensing U.S. oils. ILSAC asked the American Chemistry Council, which represents the additives industry, how it could bring a test from an outside source into the Code of Practice.

ACC noted that a foreign test can be accepted as long as it, and the test labs involved, meet the same general criteria as domestically developed tests and domestic test labs. ACC has developed a fast-track template for new tests, as a guide to judge acceptance.

The ILSAC/Oil Committee discussed how to bridge different approaches to testing in different political jurisdictions. Outside North America, for example, there may be less reliance on strict and formal checks and balances and more on informal relationships and assurances.

The committee established a small working group including vehicle manufacturers, test labs and the chemical additive industry to work with Japanese counterparts on evaluating Japanese chain-wear tests for GF-5.

Emissions System Compatibility
The ILSAC/Oil Committee established a 10-member GF-5 Emissions System Compatibility Improvement Team, chaired by Charles Sherwood of Ford Motor Co. The teams charter is to evaluate potential methods for determining the impact of GF-5 engine oil formulations on emission system function and durability, with a focus on the impact of phosphorus and sulfur on catalysts … and oxygen sensors. The team will consider chemical limits as well as physical, bench, field and engine tests, and make a recommendation on compatibility improvement by Jan.1, 2007.