The upgrade faces an ambitious schedule, especially when compared to the five years it took to develop its predecessor, GF-3, which was adopted last year.
The auto industrys timeline for GF-4 calls for first use on April 1, 2003 – just one year out – with mandatory use on October 1, 2003. Pressure to commercialize a new engine oil in sync with the 2004 tightening of emissions limits is inexorable.
An inter-industry panel, ILSAC/OIL, is at the fore in moving toward GF-4.Bob Olree of General Motors is chairman of the panel, which includes three other automaker representatives: Toyotas John Shipinski, DaimlerChryslers Tracey King and Fords Charlie Sherwood. Oil industry representatives are Pennzoil-Quaker States Cliff Venier and Valvolines Thom Smith, as API members, with Pinnacle Oils Harji Gill as the alternate. The chemical additives industry is represented by Ciba Specialty Chemicals Glenn Mazzamaro, withRich Lee of Chevron Oronite as alternate.
The panels current task is to develop a needs statement. For GF-3, that task alone took 15 months. The ILSAC/OIL panel hopes to complete this task by April or May of this year.
The documentidentifies the perils of existing phosphorus and sulfur levels. GF-3 caps the former at 0.1 mass percent but does not quantify a limit for the latter. The levels of phosphorus and sulfur commonly used in current GF-3 oils have been shown to damage catalysts, the report says.2004 model year cars will be in showrooms by mid-2003, and it is imperative that new GF-4 oils, with levels of phosphorus and sulfur that do not damage catalysts, be available at the same time.
Besides additional protection of emissions systems, ILSAC/OIL wants the next generation of motor oils to provide better fuel economy and an increase in both the retention and durability of fuel economy improvement, relative to GF-3.
TheMarch 27paper also calls for improved robustness of engine oil to better protect future engines, specifically during high-temperature, high-load operations. Further, low-temperature rheological properties must bedefined to reduce the possibility of field failures due to low-temperature viscosities.
Much of the anxiety at this stage in the GF-3 process came from the prospect of developing five brand-new engine tests, with no alternatives or backups waiting in the wings. All sides agree that development of these tests was a major reason for GF-3s two year delay.
GF-4, on the other hand, has three new engine tests, two of which have a viable alternative, and one (Sequence IIIG) which has been in development fornine months. The tests are:
(1) The Oil Protection of Emission Systems Test, OPEST, a Ford-sponsored test that measures the catalyst poisoning effect of engine oil, under development at Southwest Research Institute. Sources say that OPEST will not be completed in time for inclusion in GF-4. The acceptable alternative is to continue a chemical limit on phosphorus – an additive known to poison catalysts – by reducing it from GF-3s level of 0.10 percent mass to between 0.05 percent and 0.08 percent.
Phosphorus, however, is also a well-known, widely used antiwear agent. Prototype GF-4 oils, with lower phosphorus content and different antiwear agents, are currently undergoinglaboratory and field tests to demonstrate that wear protection can be maintained using these oils. This test regime should be completed by mid-year.
(2) The Ford-sponsored Sequence VIC 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, which can serve as the GF-4 fuel economy measurement backup test.
(3) The third test, GMs Sequence IIIG, measures wear and oxidation and will be a requirement for GF-4. GMs Olree reports that they are focusing on resolving a scuffing issue.
GF-4 oil, specifically formulated for new emissions systems at high mileage, must also protect engines in all earlier light-duty vehicles. The issue of backward compatibility is still unresolved. Later this month API will outline a way forward with a non-backward compatible GF-4 oil, and ILSAC will present a proposal on how to demonstrate backward compatibility.