GF-4: stop-and-go on the road to a new PCMO. (Cover Story).(passenger car motor oil)

It has been some time since we last looked at the ongoing saga of passenger car motor oil (PCMO) development, not because we aren't interested, but because the pace of progress has been frustratingly slow. One of the prime culprits causing the lack of progress is the performance of the new Sequence IIIG wear test, which has been called vital to the adoption of the GF-4 specification for PCMO and the next licensed category of oils.

But the IIIG is not the only difficulty that is giving the engine oil development community headaches. Continuing disagreements over phosphorus levels, category life, backward compatibility, and other issues have all conspired to keep forward movement on GF-4 at or near a snail's pace. At least this can be considered the view from outside the community of those charged with making it possible to bring the new oils to the market to meet government mandates.

In this article, we look at the current status of GF-4, including the issues that have been resolved and (perhaps more significant) those that have not. We also check in with the ASTM International unit running the testing programs for these oils (that is, the Passenger Car Engine Oil Classification Panel, or PCEOCP). It's role has changed since the last licensing category came into being. Does that new role suit it (and its members) better than when it had a more active role in establishing tests and limits for the oils?

Go: Needs Statement Is Adopted

Of relief to many who have been engaged in the GF-4 process is the issuance in January of this year of a …