Types of Automatic Transmission Fluid

There are several types of automatic transmission fluid. Transmission fluid is an oil that functions as a lubricant for the transmission's functioning parts. It also helps to regulate the transmission's internal temperature and keep it protected from wear and potential damage from harsh materials.

The transmission itself is a device connected to a vehicle's engine. It multiplies the power provided by the engine and channels it to change gears automatically as the car moves.  

Types and Brands

The two main types of transmission fluid are synthetic fluid and petroleum fluid. Synthetic is the better choice of the two because it is very effective and free of any pollutants that may be destructive. Petroleum transmission fluid, made of a refined mineral oil, is less expensive than synthetic fluid but not as effective.

The most common brand of transmission fluid is ATF brand. This brand is a "parent" brand of several smaller brands, like Dexron III, and was one of the first redeveloped transmission fluids. "Dexron" and "Mercon" brands were created by General Motors and Ford, but can be used for nearly any vehicle.

Potential Dangers

The main concern for automatic transmission fluid is heat. Because the transmission creates heat from friction, the fluid will warm up. As the heat inside the transmission increases, so does the temperature of the fluid.

The majority of transmission fluids can withstand temperatures under or at 200 degrees Fahrenheit for thousands of miles. However, fluids will begin to break down once the temperature rises above this point. Once the temperature is above 300 degrees Fahrenheit, it will only last for a few hundred miles. If the temperature goes above 400 degrees Fahrenheit, it can self-destruct in less than half an hour. This would be extremely damaging  and might even require a complete transmission replacement from a repair center such as Mr. Transmission.