CVT Fluids, What's the Score

Prior to 2000, about 80 percent of the automatic transmission fluid (ATF) market was covered by General Motors’ Dexron III, Ford’s Mercon or Chrysler’s ATF +4 standards and specifications. It was easy for an installer, mechanic or do-it-yourselfer to figure out which one to use for makeup or replacement fluid. Lubricant marketers only had to carry a couple of aftermarket fluids to meet a majority of the demands. Today, Dexron III/Mercon fluids are gone, replaced by Dexron VI and Mercon LV. In addition, they account for less than 50 percent of the aftermarket use. OEM-specific fluids with special requirements are in place and growing.

Most ATF specifications are not public or open to oil marketers. That means no one other than the OEM can approve the fluid. Those specs that are available are generally limited to one formula and are extremely expensive and time consuming to approve.

ATF installers and retail product sellers are not able to stock all the different types of ATF specified for current vehicles. In fact, there are more than 100 current transmission fluid specifications being used in North America. As most installers and independent shops are well aware, the so called “genuine” transmission fluids are often much more costly than suitable multi-vehicle alternatives. However, transmission builders have no real incentive to work together for standardized specifications, because it is more advantageous to keep their fluids proprietary. That way they can take advantage of a captive market.

The Petroleum Quality Institute of America (PQIA) recently conducted a survey with some interesting results. A majority of people agreed that “The number of ATF specifications in the market leads to misapplication,” that most consumers do not know which ATF the OEM for their vehicle is recommending and many do not read the labels on the bottle. There is also a concern that fast lube and independent repair shops may not have current knowledge as to the needs and requirements of modern equipment.

When you look at this very complex (at least specification-wise) market, you’ll find that five transmission fluids dominate. GM’s Dexron VI is No. 1 at about 25 percent of the market. Ford’s Mercon LV is in at about 20 percent, Toyota’s WS is 13 percent followed closely by transmission fluids required for various CVTs at 12 percent and Chrysler +3/+4 at around 7 percent. That’s about 80 percent of the transmission fluid market.

Four of the five transmission fluids are pretty cut-and-dried, but trying to find a “universal” CVT fluid is a whole different issue. If you check with transmission fluid experts, they will tell you they don’t know of any publicly available CVT fluid specs. The additive companies that sell transmission fluid additive packages almost all offer at least one additive that is claimed to have multi-vehicle CVT performance. They say these additives are being used in the few multi-vehicle CVT fluid applications that are on the market.

The problem with CVTs is they often suffer from mechanical design issues. This is because you are trying to lubricate a system that relies on steel-to-steel friction, yet you need to keep it quiet and minimize wear. Even with a CVT fluid that meets all of the OEM specs, you can still get a hardware failure. There have been a number of examples of past hardware problems, but they don’t get much press coverage.

One of the most common issues with transmission fluids is viscosity. Viscosity specifications are used to judge conformance to OEM specifications. Unfortunately, the fresh viscosity at 100 C (212 F) has little correlation to acceptable field performance. It is simply a benchmark. Transmissions operate in a wide temperature range, and the viscosity varies widely. In addition, many ATFs will lose viscosity quickly in service because the polymers used in the oil shear down pretty quickly.

In addition, OEMs set viscosity specs independently without regard for trying to standardize industry requirements. In some cases, the same transmission will require different viscosity specs by different car builders. In other cases, newer low-viscosity fluids have been deemed back-serviceable by OEMs for their previous higher viscosity fluids.

The obvious question then is this: With GM, Ford, Chrysler and Toyota covered, is there one CVT fluid that will cover the range of CVTs in the market place? Those additive suppliers who make transmission fluid additives for the oil marketers say that the multi-use CVT oils made with their multiuse additive should allow coverage of at least 75 percent of the market, maybe higher.