What Kind of Transmission Fluid Do I Need?

Finding out what kind of transmission fluid you need can be a challenge. Take a look at just a few of the dozens of automatic transmission fluid (ATF) specifications on the market:

  • ATF+4
  • ATF DW-1
  • Toyota ATF-WS
  • Honda/Acura DW-1

You’ve likely heard the term analysis paralysis.

That’s what many people feel when they scan the shelves at the parts store in search of transmission fluid. They just want a quart or two of ATF to top-off their vehicle, but instead they must decipher a series of hieroglyphics or face the specter of their transmission not performing properly.

What kind of transmission fluid do I need?

To answer that question, start in your vehicle owner’s manual. It’ll instruct you to use a transmission fluid that meets a certain performance specification, such as one of those listed above.

The transmission fluid specifications with which you’re likely most familiar are Ford MERCON and GM DEXRON. 

At one time, MERCON and DEXRON ATFs dominated the market and reduced your choices to a manageable few. Today, demand for those fluids has slipped below 50 percent and is declining as original equipment manufacturers (OEMs) continue to introduce their own, proprietary transmission fluid specs.

What is an ATF specification?

It’s a set of performance standards, not an actual fluid. That means you don’t go to NAPA in search of MERCON or DEXRON transmission fluid. You go in search of a fluid that meets the MERCON or DEXRON specification.

In an attempt to make it easy for you, many ATF manufacturers print ATF specs in giant letters on the label, like this.

Transmission fluid-ATF

This means the fluid was subjected to – and passed – a series of performance tests stipulated by the authors of that particular ATF specification. However, many people end up confusing the ATF specification on the label for the fluid’s brand name.

Adding to the ATF specification confusion…

Today, it’s normal for most OEMs to author their own performance specifications rather than recommend using a fluid that meets a different OEM’s specification.

You can blame it on technological advancements that have made vehicles tougher on transmission fluid than cars of yesteryear. An automaker that introduces its latest 700-hp land rocket wants to be sure you’re using a transmission fluid capable of standing up to the intense heat and stress churning through all those gears.

It may also have something to do with money. Brand XYZ would rather you buy its transmission fluid than another company’s fluid, which helps explain why some OEM-branded fluids are so expensive.

Cut through the confusion

How can we make transmission fluid selection easy? And how do we do it while meeting the performance demands of most modern automatic transmissions?

One transmission fluid to rule them all.

That’s a bit of hyperbole in honor of my favorite trilogy about hobbits and orcs, but it’s not far off.

We formulated AMSOIL Signature Series Synthetic Automatic Transmission Fluid and OE Synthetic Automatic Transmission Fluid to take the guesswork out of ATF selection. Both fluids are recommended for most of the common ATF specs on the market.

  • MERCON V? Check.
  • DEXRON III? Check.
  • ATF+4? We cover that, too.

If you tow, haul or engage in other types of severe service, use Signature Series Synthetic ATF. If you stick to the highway and mostly run to work and home, OE Synthetic ATF is your best bet.

How to Check Transmission Fluid and what kind of transmission fluid do I need.

Suitable for use in applications calling for MERCON ULV and DEXRON ULV

AMSOIL Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid is suitable for use in applications that call for two of the latest ATF specs in the industry: MERCON ULV and DEXRON ULV.

Ford and GM worked together to create these two specs for their 10-speed Ford and GM transmissions available in some 2017 and later Ford Mustangs, Ford F-150s, Chevy Camaros and Cadillac Escalades, among other vehicles.

These transmissions use ultra-low-viscosity transmission fluid to help reduce energy lost to fluid friction to maximize fuel economy.

How to check transmission fluid

It’s a good idea to check your vehicle’s transmission fluid about once a month to monitor fluid level and condition. Check the fluid immediately if the transmission jerks, hesitates or shifts hard. Here’s how to do it.

Time needed: 15 minutes.

How to check transmission fluid

  1. Ensure the transmission is warm

    Obtaining a correct reading on the dipstick requires the fluid to be warm and the engine to be running. To begin, park your vehicle on a flat surface, apply the parking brake and idle the engine until warm. It helps to drive the vehicle for a short period to raise the temperature more quickly. Some OEMs also recommend shifting through the gears to circulate the fluid prior to checking, so consult your owner’s manual.

  2. Locate the dipstick

    Pop the hood and locate the transmission fluid dipstick, which serves double duty as the fill tube. It’s often located near the back of the engine compartment and shouldn’t be too tough to find. You can always check the owner’s manual for the location if it proves elusive.

  3. Check the fluid level

    Pull the dipstick and wipe with a clean rag. Insert the dipstick until it’s completely seated. Withdraw it and check the fluid level. The dipstick may have a cross-hatch pattern in which the fluid level should fall. Others may have a “hot” and “cold” line. The fluid should be close to the “hot” line.

  4. Add fluid if needed

    If the fluid is low, add the recommended transmission fluid to bring to the correct level. You’ll probably need a long-neck funnel with a small-diameter opening at the end.

Checking transmission fluid in a “filled-for-life” transmission can be tricky, but it is possible. Check out this post for details.

Use the AMSOIL product guide to find the right transmission fluid

We take convenience a step further with our online product guide, which tells you which transmission fluid your vehicle needs. Just enter the year, make, model and engine for immediate results.

So, when it comes time to change your transmission fluid, cut through the confusion by remembering these six letters: AMSOIL.

Updated. Originally published June 26, 2017.


  1. You’re selling your products to car guys, yet you talk to us like we’re elementary school teachers, that just need to be reassured that everything will be fine if we use AMSOIL products. Nothing about what your products are based of. Are they POA dominant? Are they mPOA dominant? What exactly are they made up of, cheeriness and good faith?

    1. Hi Michael,

      I appreciate your desire to use the best transmission fluid possible. And I realize the desire to use PAO-dominant lubricants arises from good intentions. But, at the risk of being obvious, it’s important to point out that you’re not just putting base oil in your tranny, you’re installing a fully formulated transmission fluid. The entire formulation, including the additives, must be considered. At the end of the day, the base oils that go into the fluid aren’t as important to your transmission as the performance that comes out of the fluid.

      Like other companies, we hold formulation details as proprietary and don’t divulge trade secrets. Revealing such details would give the competition an advantage that you can bet they aren’t going to give us.

      Instead, we invite you to judge AMSOIL Signature Series Synthetic Transmission Fluid based on the test data, which you can see here.

      If it meets your performance threshold, great; I hope you’ll consider using it.



  2. Quelle huile pour boîte de transfert
    Ford ranger 2011 4×4 V6
    4.0l – 5 vitesses automatique
    Ford recommande XL-12
    Es-que amsoil ATF OM OK.

  3. Hi John,
    I’m about to change transmission fluid on my 2014 F150 Raptor. which one would you recommend specifically for this vehicle?
    I also want to change transfer case fluid and front and rear bridges. I do some towing and hauling. Thank you. Ralph

    1. Hi Ralph,

      Our product guide provides recommendations for all the products we make for your Raptor. Take a look, and if you have any follow-up questions, contact AMSOIL Technical Services and they’ll be glad to help (715-399-TECH). Thanks!


  4. Hi, I’m looking for a recommendation which fluid to put in my transmission. It’s the M5od-r1hd manual transmission in my 07 Ford Ranger. I used another brand synthetic ATF last time I changed it and it still is difficult to shift into 1st and sometimes into other gears, as well. It doesn’t want to go and sometimes when it goes in, it chatters. Will Amsoil signature series ATF or Amsoil Torque-Drive help this issue? Or do you recommend another one of the Amsoil products? Thanks

    1. Hi Mike,

      We recommend AMSOIL Signature Series Automatic Transmission Fluid in that application. While it provides excellent protection and performance, we can’t make a definitive prediction it’ll fix your chattering problem since all transmissions are different.



    2. I’m also wondering if this is the best fluid to use for my 07 Rangers power steering and transfer case.

      I know there was some confusion years back, about whether or not ATF should be used in Ford transfer cases around the year 2007, because it allegedly would destroy them. And specific transfer case fluid, was recommended by Ford. Does Amsoil ATF meet the requirements of Fords transfer case fluid? Thanks again.

  5. I can’t seem to confirm that Amsoil’s Signature Series Multi-Vehicle Synthetic Automatic Transmission Fluid (ATF) meets the Mazda ATF special spec for the 2006-2015 MX-5 Miata automatic transmission. I can see from the online listing of specs it meets that is appears to be fully compatible, but I’d like rock-solid confirmation.The spec is called (JWS 3309 or Toyota T-IV).


    1. Hi Heman,

      I consulted with our Technical Services Department and here’s what they said:

      Mazda requires using an oil that meets the JWS 3309, also known as Toyota Type T-IV, specification. AMSOIL Signature Series Multi-Vehicle Synthetic Transmission Fluid is a Type T-IV fluid. See its product data bulletin for the specs.



  6. I have a 1979 Fiat 124 Spider 2000 with a GM automatic transmission. The owner’s manual call for DEXRON II ATF. What do you hav to match?

  7. Excellent blog, I thank the author for this useful information. This is important to know that which one is the right transmission fluid. By following your guidelines, now I can choose correct ATF.

  8. Thanks for sharing such a useful information with your video, after reading your blog, I came to know how to choose the correct transmission fluid by following your guidelines.

  9. Been using all products seen 1973. I waited long time for AT oil. Great , last longer and runs cooler. Two thumbs up.

Leave a Reply