Texaco Havoline Automatic Transmission Fluid did not fare as well. Although it passed the 300-hour test requirement with a 10.66 percent viscosity increase, viscosity increased significantly as the test was allowed to continue. It exceeded the 25 percent viscosity increase mark after 500 hours, then soared to a 3,539.04 percent viscosity increase after 1,012 hours.

Automatic transmission fluid is an important component in an automatic transmission. Fiber plates contact metal plates, bearing contact bearing races, gears contact gears, and automatic transmission fluid comes in contact and lubricates all of them. Cold temperatures can cause conventional automatic transmission fluids to increase in viscosity, causing a decrease in automatic transmission efficiency. This efficiency decrease is often referred to as sluggish operation; which demands more energy from the engine to actuate all the parts that come into contact with the automatic transmission fluid. AMSOIL Synthetic oils are not affected by temperature reductions as much other oils and will have better low temperature pumpability and therefore better mechanical efficiency. Better efficiency can provide better fuel economy.

75% of all transmission filters today are not a screen, they are made of felt. They cannot be cleaned. The filter must be replaced. Clogged filters restrict fluid flow, which lowers pressure to clutches and bands, which will eventual burnout the transmission.

AMSOIL Synthetic low-Viscosity Automatic Transmission Fluid is formulated with the highest-quality components to exceed the most stringent industry standards. Low-Viscosity Automatic Transmission Fluid is a fuel-efficient fluid, it has demonstrated its ability to protect as well as or better than higher-viscosity fluids in the most severe industry tests.

In a study conducted by General Motors, it was determined that an Automatic Transmission Fluid operating temperture of 175f. would translate into a service life of 100,000 miles for an automatic transmission. That life would be reduced by 50 percent for every 20f. increase in fluid operating temperture. This demonstrates that small temperture changes can result in big differences in transmission life expectancy. The use of AMSOIL ATF can promote component longevity through reducing operating temperatures by as much as 15 to 30f. This particularly significant for applications equipped for towing or hauling heavy loads.

Viscosity requirements for an automatic transmission differ by application. these products are typically multi-viscosity fluids. However, single grades fluids are also commonplace. The multi-viscosity products generally contain viscosity index improvers which allow for the low temperature performance typically required of ATF fluids.

The low temperature properties of an Automatic Transmission Fluid have become increasingly important in recent years. For example, one of the key differences between Dexron II and Dexron III fluids recommended by General Motors is the increased ability of the Dexron III product to function at lower operating temperatures. The same holds true for the Mercon and Mercon V fluids, which are recommended by Ford.

The coefficient of friction of a fluid affects the shifting characteristic of an automatic transmission. Whether the shifting characteristics of a transmission are smooth and subtle or aggressive will depend on its design and the fluid used. It is, therefore, prudent to use a fluid matching the requirements of the transmission manufacturer.

As with any hydraulic fluid, transmission fluid should be regulated carefully. If you own an older car, you should be checking the fluid at least twice a year to ensure peak performance. Remember that your car will begin to shift poorly without the proper amount of fluid. This lack of lubrication also puts unneeded stress on the engine and can lead to more serious problems.