Fresh fluid provides the right friction for gears.
Additives prevent sludge buildup inside the valve body. Quick Maintenance Tips
Checking your transmission fluid is a quick way to gauge your vehicle's health. While it shouldn't have a "taste," its smell and appearance tell you everything you need to know. The "Taste" Test (Visual and Olfactory)
Dark brown or black fluid with a acrid smell means it's overheating.