What weight is transmission fluid?

What weight is transmission fluid?


Transmission fluid is a vital component in a vehicle’s transmission system. It serves multiple purposes, including lubricating the moving parts, cooling the transmission, and facilitating smooth gear shifting. One common question that arises is, “What weight is transmission fluid?” In this article, we will explore the weight of transmission fluid and its significance in vehicle performance.

Understanding Transmission Fluid Weight

Transmission fluid weight refers to its viscosity, which is a measure of the fluid’s resistance to flow. It determines how easily the fluid can move through the transmission system. The weight of transmission fluid is typically represented by a numerical value followed by the letter “W” (e.g., 75W-90). The “W” stands for winter, indicating the fluid’s performance in colder temperatures.

Types of Transmission Fluid

There are different types of transmission fluid available, each with its own weight or viscosity rating. The most common types include:

1. Automatic Transmission Fluid (ATF): ATF is designed for use in automatic transmissions and comes in various weights, such as ATF+3, ATF+4, and Dexron. The weight of ATF is typically denoted by a number, such as ATF+4, which indicates its viscosity at both high and low temperatures.

2. Manual Transmission Fluid (MTF): MTF is specifically formulated for manual transmissions. It also comes in different weights, such as 75W-90 or 80W-90. The first number represents the fluid’s viscosity in colder temperatures, while the second number represents its viscosity in higher temperatures.

Choosing the Right Transmission Fluid Weight

Selecting the correct transmission fluid weight is crucial for optimal performance and longevity of the transmission system. The manufacturer’s recommendations should always be followed, as they specify the appropriate weight for a particular vehicle model. Using the wrong weight of transmission fluid can lead to poor shifting, increased wear and tear, and potential damage to the transmission.

Factors Affecting Transmission Fluid Weight

Several factors can influence the choice of transmission fluid weight, including:

1. Climate: The climate in which the vehicle operates plays a significant role in determining the appropriate transmission fluid weight. Colder climates require a lower weight fluid (e.g., 75W-90), while hotter climates may necessitate a higher weight fluid (e.g., 80W-90).

2. Driving Conditions: The type of driving conditions also affects the choice of transmission fluid weight. Heavy towing, frequent stop-and-go traffic, or hilly terrains may require a higher weight fluid to withstand the increased stress and heat generated.


In conclusion, the weight of transmission fluid refers to its viscosity, which determines its flow characteristics. Automatic transmission fluid (ATF) and manual transmission fluid (MTF) come in various weights, with each weight serving a specific purpose. Choosing the right transmission fluid weight is essential for optimal performance and longevity of the transmission system. Factors such as climate and driving conditions should be considered when selecting the appropriate weight. Always refer to the manufacturer’s recommendations for the correct transmission fluid weight for your vehicle.


– www.carcare.org
– www.auto.howstuffworks.com
– www.transmissionrepaircostguide.com