The specification, which was completed earlier this year, has not yet been posted publicly, Johnson acknowledged. He said GM plans to set up a web site with more information about GEOS.

GM has more than 20 different engine sizes made in 18 plants worldwide, and needs the same quality oil available everywhere, said Johnson. GEOS actually consists of two specs, he continued: GEOS-A defines factory-fill and service-fill engine oils for gasoline-fueled engines, and GEOS-B defines factory-fill and service-fill oils for diesel-fueled engines, as well as gasoline-fueled engines in Europe.

The benefits of the new specification include fuel economy, engine protection, fewer service visits, reduced maintenance costs and reduced emissions. “GM is attacking fuel economy on many fronts,” Johnson said, “and GEOS is one.”

Pressed for specifics on how GEOS differs from the current GF-4 or proposed GF-5 specifications, Johnson would only say that “GEOS is an internal [GM] initiative and likely to be an evolving spec. It will use some European tests.”

Asked about warranty ties and licensing, Johnson said that GM owners’ manuals “will recommend” the new spec just as they recommend current specifications, and GM is considering a licensing program similar to the Dexron transmission fluid licensing program, but has not finalized it.

Given GM’s significant involvement in GF-5 (GM’s Jim Linden chairs ILSAC, the committee developing GF-5), it’s likely that GEOS will incorporate much if not all of that specification, combined with European tests not presently included in the North American and Japanese standards.