By David McFall
 
Springtime has put some welcome wind back into the sails of the next gasoline engine oil upgrade, GF-4.  Auto and oil industry representatives are expected to agree to the final test battery and final test limits for the spec by June 26.
 
The first front on which GF-4 is making significant progress is the testing matrix for the single, critical new engine test, the 100-hour, General Motors-sponsored Sequence IIIG, which measures high temperature deposits, wear and oxidation. The testing matrix is now under way under the auspices of ASTM’s Passenger Car Engine Oil Classification Panel, in the San Antonio laboratories of Southwest Research Institute and Perkin Elmer Laboratories. 
 
This test program is critical to ensure that the test maintains precision and reproducibility over an extended test program. The 24-test battery, four tests run on each of six test stands, is planned to be completed by the end of May. Industry statisticians will then evaluate the data, develop a consensus report, and present it to the IIIG Surveillance Panel, which will present it to ASTM’s Passenger Car Engine Oil Classification Panel at their next scheduled meeting in Norfolk, Va., on June 17.
 
It’s a tight schedule but as of yesterday, nearly halfway through the program, John Zalar, director of ASTM’s Test Monitoring Center and program manager for the matrix, reported that, of 14 tests begun, eight have been completed successfully with six still running. Of critical importance, no tests have been aborted for any reason.
 
The second advancing front for GF-4 is the inter-industry ILSAC/OIL committee,  which is nearing agreement on the technical composition -- that is, the test battery -- of the new category and, most important, setting limits for these tests.
 
Chaired by GM’s Bob Olree, the committee met May 8 in Romulus, Mich.  The group is comprised of three representatives of the auto industry, two from the oil industry and one from the chemical additives industry, with one alternate person for each industry.
 
Two issues were settled at last week’s meeting.  One related to SAE J300, the Engine Oil Viscosity Classification Standard, which is to be included in the category without adding a proposed GM requirement for the Mini-Rotary Viscometer test (MRV TP-1), which measures low temperature pumping viscosity.  
 
The other settled issue relates to the Gelation Index, which is derived from the Scanning Brookfield Test, which also measures low temperature viscosity as well as gelation, the tendency of an oil toward solidification.  This test will now be run to a temperature of 2 degrees C below the MRV TP-1 temperature and the Gelation Index will be set at 12. 
 
Several other items are under active consideration, including limits for the TEOST MHT-4 test, which measures high temperature deposits, limits for the Sequence IVA test, which measures valve train wear, and trade-offs between fuel economy as measured by the Sequence VIB test and deposits as measured by the Sequence IIIG. 
 
A new concept presented by the oil industry side was to remove a minimum phosphorus limit if the automakers would agree to a maximum sulfur level of 0.8 percent. That is, the OIL side proposed a phosphorus maximum of 0.08 percent and a sulfur maximum of 0.8 percent with no minimums. The automakers agreed to discuss the proposal with representatives of the Japanese Automobile Manufacturers Association. Fortuitously, GM’s Mike McMillan and DaimlerChrysler’s Tracey King were scheduled to leave the next day to meet with JAMA representative in Japan.
 
Olree has scheduled two more ILSAC/OIL meetings, June 9 and 26.  As currently planned, the meeting on June 26 will see the final test battery accepted along with final test limits. That document will then be circulated to all interested parties for comment.