How do I know what transmission fluid to use?
The right transmission fluid is the one specified by your vehicle’s manufacturer. Start with the owner's manual or the label on the transmission to find the exact specification (for example Dexron VI, ATF+4, or Toyota WS). Use only OEM-approved ATF and avoid guessing or mixing fluids unless the manufacturer explicitly permits it.
In more detail, identifying the correct fluid involves checking official sources, understanding common specification codes, and knowing when special fluids are required (such as for CVTs or DSGs). This guide walks you through where to look, how to interpret the specs, and what steps to take to ensure you choose the right fluid for your exact model and year.
Where to Find the Official Specification
Most reliable guidance comes directly from the car’s documentation or the supplier’s labeling. Look for the exact ATF specification and viscosity listed by the manufacturer. If the original documentation isn’t readily available, there are still solid ways to confirm the right fluid without risking damage.
Owner's manual and service labels
The manual, or a label on the transmission or under-hood area, will specify the required ATF type (such as Dexron VI or ATF+4) and sometimes the viscosity. This is the primary, authoritative source.
VIN-based online lookups
Manufacturers and trusted third-party portals offer VIN-based lookups that return the exact ATF specification for your vehicle’s year, make, model, and market. This is especially helpful if you no longer have the manual or if the vehicle was imported or modified.
What To Do If You Can’t Find the Spec
Ask a dealer or trusted repair shop
If you cannot locate the specification in manuals or on the vehicle, contact an authorized dealer or a reputable shop. They can pull the exact specification from the vehicle’s service records or manufacturer database using your VIN.
Avoid guessing or mixing fluids
Using a fluid that does not match the OEM specification can cause shifting problems, increased wear, or transmission failure. Do not mix fluids from different specifications unless the manufacturer clearly allows it.
Step-by-step Guide to Picking and Using the Right ATF
Here is a practical, step-by-step approach to determine and apply the correct fluid.
- Consult the owner's manual or the transmission label to identify the exact specification and viscosity (for example Dexron VI, ATF+4, or WS).
- Determine whether your transmission is standard automatic, CVT, or DSG, since CVTs/DSGs often require fluids specifically formulated for those designs.
- Ensure compatibility: do not mix fluids unless the manufacturer explicitly allows it; use only fluids that meet the OEM specification.
- Choose a reputable brand and source that advertises the exact OEM specification rather than a generic “universal” ATF.
- If available, use a VIN-based lookup to confirm the exact specification for your model and year.
- When performing a change, follow the recommended service procedure and fill to the correct level; if you’re unsure, consult a professional.
Following these steps helps ensure you use the correct transmission fluid and protect your transmission’s longevity.
Common Transmission Fluid Specifications and What They Mean
Below is a quick reference to the main OEM specifications you’re likely to encounter. Always verify against your manual before buying or filling.
- Dexron VI — Widely used in GM transmissions and adopted by many other makes; designed as a modern replacement for older Dexron III in many applications.
- Mercon LV — Ford’s modern specification for many of its automatics; not generally interchangeable with Dexron fluids unless the manufacturer explicitly states compatibility.
- ATF+4 — Mopar specification used by many Chrysler/Jeep/Dodge transmissions; not compatible with Dexron/Mercon in most cases; verify for your exact model.
- Toyota WS — Toyota/Lexus modern specification for many automatic transmissions; not cross-compatible with Dexron or ATF+4 unless explicitly stated.
- CVT fluids (special formulations) — Used for continuously variable transmissions and DSGs; each manufacturer often has its own spec (for example NS-2 or other brand-specific fluids); not interchangeable with standard ATF unless approved by the manufacturer.
In every case, the exact fluid you should use is defined by the OEM specification for your vehicle. When in doubt, contact a dealer or a qualified technician, and avoid guessing or mixing fluids from different specifications.
Important Cautions
Using the wrong transmission fluid can lead to poor shifting, slipping, or long-term damage. Do not rely on fluid color or feel to guide your choice—the manufacturer’s specification is the only reliable guide. CVTs and DSGs require fluids designed specifically for them; never substitute a standard ATF in a non-ATF–designed transmission.
Summary
The key to knowing what transmission fluid to use is the manufacturer’s specification for your vehicle. Start with the owner’s manual or a transmission label, ensure any fluid you buy meets that exact OEM specification, and avoid mixing fluids. If you can’t confirm the spec online, call your dealer or use a VIN lookup to get the precise requirement for your car. Following these steps helps protect your transmission and maintain smooth, reliable shifting.
How do I find out what transmission fluid I need?
You can find the recommended transmission fluid type specific to your vehicle in your Owner's Manual, or you can refer to Ford's Chemicals and Lubricants website.
Are all automatic transmission fluids the same?
No, not all automatic transmission fluids (ATFs) are the same; they have different formulations that are specific to certain vehicles and transmission types. Using the wrong fluid can cause damage and poor performance. You must check your owner's manual for the specific fluid your vehicle requires, which will have a specific specification like GM's Dexron VI or Ford's Mercon V.
This video explains why there are different types of automatic transmission fluids: 58sProject FarmYouTube · Jun 4, 2023
Why different fluids are needed
- Vehicle manufacturer requirements: Each car manufacturer develops specific standards for its transmissions because they are built with different materials and designs.
- Transmission type: Different types of transmissions require different fluids:
- Continuously Variable Transmissions (CVTs): Use specialized fluids that are not compatible with conventional automatic transmissions.
- Dual-clutch transmissions (DSGs): Have unique fluid requirements based on whether the clutch is wet or dry.
- Older vehicles: Older vehicles may require specific fluids, such as the Type F fluid for older Fords, that are not compatible with newer, modern fluids.
- Performance needs: Different fluids contain varying amounts of additives designed to meet the performance demands of a specific transmission.
How to find the right fluid
- Consult your owner's manual: This is the most important step, as it will specify the correct fluid specification your vehicle needs.
- Look for specifications: Find the specific specification on the fluid bottle, such as "Dexron VI," "Mercon V," or "ATF+4".
- Consider universal fluids: Some "universal" fluids are designed to meet multiple specifications, but always check if they cover the one listed in your manual before using them.
- Avoid using the wrong fluid: Using a fluid that is not the correct specification can cause poor performance and lead to expensive long-term damage to your transmission.
What happens if you use the wrong kind of transmission fluid?
Using the incorrect fluid could potentially damage the clutches and the timing belt.
Does it matter what type of transmission fluid I use?
Yes, it matters significantly what transmission fluid you use because the wrong type can cause serious damage, leading to issues like rough shifting, shuddering, or complete transmission failure. You should always use the specific type of fluid recommended by your vehicle's manufacturer, which can be found in your owner's manual.
Why the correct fluid is critical
- Different fluid properties: Automatic and manual transmissions require different fluids with different characteristics. Automatic transmission fluids (ATFs) are designed for things like friction and anti-foam, while manual transmission fluids need to provide wear protection and synchronize protection.
- Manufacturer specifications: Different car models have different transmission designs that require specific fluids with unique additive packages and viscosity levels. Using a fluid that isn't compatible, even one that seems similar, can cause problems.
- Avoid major damage: Using the wrong fluid can lead to a range of issues, from subtle performance problems like erratic shifting and poor acceleration to severe and irreversible damage to the transmission.
How to choose the right fluid
- Check your owner's manual: This is the most reliable source for the specific fluid type, brand, and specifications your vehicle needs, such as Dexron VI or Mercon LV.
- Look for specific OEM recommendations: Transmission fluids are not interchangeable, even if they are the same color or labeled "universal". Always check for the official OEM (Original Equipment Manufacturer) recommendation for your specific vehicle.
- Consider driving conditions: If you frequently drive in extreme heat or tow heavy loads, synthetic fluids are often a better choice as they can handle higher temperatures.
- Use reputable brands: When you need to replace or top off your fluid, choose a quality product from a respected brand.
