Which Transmission Fluid Should I Use for My Automatic Transmission?

When performing routine maintenance on your vehicle, one of the things on your checklist should be fluid levels, including transmission fluid. So where do you check it, what type of transmission fluid should you use, and what is its purpose?

Transmission fluid is meant to keep the metal parts inside the gearbox from wearing down, to keep certain parts of the transmission cool, and to let your vehicle shift easily while protecting the parts that rub together.

How to Check Transmission Fluid

  • Transmission fluid should be checked regularly to make sure there are no leaks leading to low fluid levels and to make sure the fluid isn’t worn out, allowing damage to occur.
  • Before getting started, gather a light-colored towel and find the transmission dipstick, which should be located near the oil dipstick and labeled appropriately. If you can’t locate the dipstick, check your owner’s manual. Some cars today aren’t equipped with dipsticks, likely because they don’t want you to mess with it and want you to take it to your dealer instead.
  • When ready, park your vehicle on level surface, engage the parking brake and start the engine. Leave the car in neutral or park. Let your vehicle warm up and continue to run throughout the operation unless the owner's manual says otherwise. (Be aware that some automatic transmission fluid levels are checked with the engine off. Check the owner's manual.)
  • Remove automatic transmission fluid dipstick. Wipe clean, reinsert fully and remove again.
  • Observe markings at end of dipstick. Your dipstick might have two markings for “full”—one warm, one cold. If the automatic transmission fluid level does not come up to the “warm” line, you'll need to add automatic transmission fluid.
  • Also look at the fluid color—it should be a bright red; smell—it should not smell burnt; and consistency—the fluid should be clear of any contaminants.

Which Type of Transmission Fluid Should You Use?

There are two primary types of transmission fluid, automatic and manual. Automatic transmission fluid (ATF) is used in all cars that have automatic transmissions and in certain modern manual transmission cars. Manual transmission oil is the fluid used in some manual cars; it is never used in automatic transmission vehicles. In some cases gear oil is used within manual transmissions.

Underneath the umbrella of ATF are several varieties, Type F, Dexron III/Mercon, HFM-Style Fluids used by Chrysler, Honda/Acura, Jeep/Eagle, Hyundai, Toyota/Lexus, Saturn, Sterling.

Some of these fluid types are interchangeable though it is important to check with your owner’s manual to be sure. Numerous manufacturers formulate fluids that meet the individual standards of those various ATF fluids. It is important to review the “spec sheet” to validate your vehicle’s fluid requirements has been tested and approved for any fluid used in your transmission.

Increasingly more vehicles require a synthetic variation of ATF. Synthetic transmission fluid tends to be more expensive however it carries numerous benefits compared to regular ATF. It has a superior ability to handle heat while being more resistant to oxidation and rust. Drivability and smooth shifting is also enhanced. These features can save you money in the long run due to its ability to extend transmission life.

Once you know which fluid is correct for your vehicle, you can complete your maintenance check and add fluid if you are low. Do that by inserting a long funnel into the ATF dipstick hole. Carefully add the fluid in small increments and recheck the level each time until the fluid level reaches the “warm” line. Be careful not to overfill or spill ATF on hot engine parts. Reinsert dipstick fully.

Need Help?

If you would rather not mess with ATF and would feel better if a professional helped you find out which type of fluid your vehicle uses, bring it in to us at Advanced Transmission Center. We will answer all your questions and, if you would like, perform a TrueTest Inspection while you are there, so you can be assured that all is in good working order.

Call our Northwest Denver center at 303-647-5257, our Southwest Denver center at 303-816-3856 or contact us online today so we can take a look at your transmission fluid levels and also evaluate the condition of the fluid.

Written by Advanced Transmission Center