Announced April 1 and presented yesterday at a lubricants meeting during the SAE Congress in Detroit,the new spec is part of a trend of change for the ATF market. Performance requirements have risen steadily the past few years to accommodate transmission design changes as well as pushes by automakers for fluids to last longer and perform better.

GM introduced the Dexron-III(H) spec just two years ago, but decided it needed to upgrade again to accommodate the Hydra-Matic 6L80, its first six-speed automatic transmission. As far as the transmission fluid is concerned, the biggest change with the 6L80 is that it puts clutch interfaces in direct contact with each other, rather than using a buffer such as a freewheeler between them. Having direct contact improves the speed and efficiency of power handoffs between clutches, but it also requires greater precision to keep those interactions consistent.

With this new transmission, we have to be much more precise in our lubricant performance,Steven Kemp, engineering group manager for GM Powertrains Fuels and Lubricants Department in Pontiac, Mich., told Lube Report Monday. Without that improvement, you could have inconsistent shifts, and that could potentially detract from customer satisfaction.

GM, Afton and Petro-Canada sought to develop a fluid with a more consistent viscosity profile compared to Dexron-III(H); that would perform more consistently in extreme conditions; and that would degrade less over time. They achieved these improvements, officials said, by raising requirements for oxidative and shear stability, foam performance and protection against pitting.

GM claims that Dexron-VI delivers more than twice the durability and stability in friction tests than do existing fluids. Although the company is still gathering data, it expects this to lead to a drain interval extension of roughly the same order.

The result [of the effort] is a new fluid that significantly outperforms existing fluids in every aspect, said Roy Fewkes, driveline fluids group leader for GM Powertrain. In fact, we have had to significantly extend the length of our durability tests to fully test the fluids capability.

In every parameter, this is a significant improvement over fluids that are already on the market,John Sunne, Aftons director of original equipment manufacturer liason in Southfield, Mich., told Lube Report.Meeting all of the requirements was extremely difficult.

GM said it incorporated fleet tests and the requirement for compatibility with other chemistries to further ensure product performance. But it also acknowledged the difficulty of these requirements.

We need to make sure there is a consistent product [in the aftermarket], so weve set up these additional hurdles, Kemp said. [Gaining approvals] is not going to be a simple stroll through the park as has been the case with previous specifications.

Observers agreed that Dexron-VI is tougher than existing ATF specifications, though some described it as an incremental step in ongoing market trends.

It will require higher quality base stocks, and the fluid itself will have to be more shear stable, said Craig Paterson, product manager with Lubrizol Corp.s ATF segment in Wickliffe, Ohio. We believe it will take a little bit longer to gain approval, due to the additional tests. There will be a definite increase in costs.

Changesalso have been made to the licensing program. Rather than licensing fluids directly, GM will license chemistries that meet the specification’s requirements, leaving it to additive companies to issue sub-licenses for approved finished fluids. Afton, currently the only company with an approved chemistry, said it will not charge separate licensing fees. GM charges an annual fee of $3,000 per product under the old program.

Involvement in the spec appears to be a coup for Petro-Canada and Afton, which won contracts to be exclusive suppliers of base oil and additive chemistry, respectively, for fluid installed in new vehicles. (For factory fill, the fluid is referred to as RDL-3434.) GM began installing the new fluid at its Willow Run plant in Ypsilanti, Mich., April 4 and will convert other facilities in coming months. It also said Dexron-VI will be available through its authorized dealerships and service centers this summer.

The big question is how prevalent Dexron-VI will become in the service fill market, which trumps factory fill volumes. The fluid will become GMs recommendation for service fill on all cars and light trucks, although not in time for owners manuals of some model year 2006 vehicles. Moreover, the automaker is already recommending Dexron-VI for service fill in existing vehicles, noting its compatibility with transmissions built before model year 2006. To encourage the switch, the company will cease to issue Dexron-III(H) licenses at the end of 2005, meaning all such licenses will expire by the end of 2006.

Some observers said it remains to be seen whether Dexron-VI becomes the fluid of choice for service fill for GM drivers. If the new fluid costs much more, they suggested, it could encourage continuing demand for Dexron-III products, even after they are no longer licensed.

If Dexron-VI does become a workhorse spec, it could complicate the ATF market in North America. Currently, a bit more than half of ATF sales by volume in the region are products that carry licenses for both Dexron-III and Fords specification, Mercon. According to the National Petrochemical and Refiners Association, ATF sales in the United States totaled 178.4 million gallons in 2003. Products carrying Dexon-III and Mercon licenses accounted for 96.6 million of those gallons. Observers speculated that Dexron-VI may break that link.

This looks to me like something that is going to lead to further segmentation of the market, said an official with an oil company, who spoke on condition of anonymity.