Best transmission fluid for automatic, manual, and CVTs vehicles review 2021

Choosing the correct transmission fluid for your vehicle is one of the most important things to do since it can keep your car safe and prevent unwanted vehicle repair costs.

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But, how to choose the best suited for your vehicle is not an easy job because this depends on specific kinds of transmission: manual, CVT, or automatic. Also, whether should you go with OEM fluid or not?

I will blow your worry away with an appropriate buying guide and product review of the best TF for automatic, manual, and CTVs transmissions.

Let’s dive in!

Transmission fluid compatibility chart

Dexron VI

This fluid is compatible with the newest GM models and some vehicles that use any earlier version of Dexron before. You can also use it in models that use GM transmissions like BMW.  

Mercon V

It is compatible with the latest Ford models and most transmissions that previously used Mercon.  

ATF+4

ATF+4 works well with Chrysler vehicles that are produced in prior years. Besides, you can use it for most cars that call for Mercon and Dexron fluids.    

Multi-Vehicle Synthetic Transmission Fluid

It is compatible with lots of automatic transmissions. They include Ford, GM, Nissan, Honda, Toyota, Volkswagen, Volvo, and more.

CVT

Works with vehicles that have CVT transmission. Such cars include Honda Accord, Toyota Camry, Subaru Forester, Nissan Altima, Honda HR-V, Audi A4, and Toyota Prius. Besides, the fluid is compatible with Mercedes-Benz A and B class, Toyota Highlander Hybrid, and more. 

Type F

You can use it for all 1976 and earlier Mercury, Lincoln, and Ford models of light trucks, vans, and cars. It also works for all 1977 to 1980 models with ESW-M2C33-F or no number stamped on the dipstick. 

Check compatibility chart below to know your vehicle’s fluid spec.

Considerations

ransmission fluid helps lubricate and cool the vehicle’s transmission to make the driveability better and enjoy a smooth drive. The better the quality of TF, the better will be the performance of your car.

Now, let’s move on to the considerations of transmission fluid.

OEM or Aftermarket? 

When it comes to transmission fluid, consumers usually question whether they should use OEM or Aftermarket transmission fluid or not. 

OEM FLUID

OEM is an abbreviation of Original Equipment Manufacturer. The original manufacturer makes this component. OEM Fluid is the same lubricating oil that came with your car at the time of buying. Many consumers use OEM Fluid as their services are covered under the warranty claim of their vehicle. However, if the vehicle is 3 to 4 years old or your company does not provide a warranty, you will have to pay the amount. 

Aftermarket Fluid

The original company does not compose aftermarket fluids. The fluid is used to make the gears lubricated for better performance. Aftermarket manufacturers thoroughly examine your vehicle and detect the reasons for failure in existing OEM fluids. Aftermarket Transmission Fluid is ideal for consumers who are driving their cars for more than four years. After four years, your original manufacturer will take full payment for providing OEM Fluids.

In a nutshell, if you fully trust the original car manufacturer, then go with the OEM. Moreover, you can claim your warranty to cover the damage then OEM Fluid is better for your vehicle. Contrarily, if you want to identify the root cause of the damage with proper care, go with aftermarket fluid.

An Explanation of the Numbers Written on Product

SAE  

When you check the label on the product, you may see SAE 5W-30, SAE 10W-40, or other numbers with SAE at the beginning. SAE stands for the Society of Automotive Engineering. The W stands for winter, and the number before it indicates the flow of oil at 0 degrees Fahrenheit. It means, the lower the number, the less the fluid will thicken in cold conditions. The other two numbers mentioned after the W indicate how quickly the oil will thin out when the temperature is high. 

For example, at a higher temperature, 10W-30 will thin out more rapidly than 10W-40. So, it is better to choose low viscosity-grade oil at low temperatures to facilitate lubricant circulation in your vehicle during a cold engine start. It means 0W or 5W would be ideal if you live in a country where the weather is usually cold.      

 GL rating

It shows the fluid’s ability to function effectively in different driving conditions. GL-4 and GL-5 are the most common ones. Typically, most of the cars you drive daily use GL-4. However, high-power cars, trucks, and vehicles used for high-stress and high-performance applications typically use GL-5 oils.    

Generally speaking, the best is to look at your car owner’s manual. The viscosity grade and GL rating that is particular to your vehicle is specified there.   

Best automatic transmission fluid  

Best in Price and Winter Driving: ACDelco 10-9395 Dexron VI

The ACDelco 10-9305 DEXRON-VI ATF provides a calming effect to drivers with smooth and consistent gear shift transmission. This performance in your car will help you have better gear changes in tough terrains and high speed. One nice thing with this ATF is the ability to perform optimally even in extremely cold weather performance giving a good feeling for winter driving.

Additionally, with improved friction resistance, your car will have more power to reduce fluid foaming and clogging of transmission pipes. One thing you will notice is the antioxidation power in your gearbox with less corrosion and rust. All this translates into your wallet with some fuel efficiency and longer efficient transmission life in your engine.

Cheap things are expensive as all people tend to use them, and they do not stay for long in service. Do not lose me on the way. What I mean is instead of going for non-certified aftermarkets, this ATF can be a stable replacement for any car with DEXRON specification range such as DEXRON II AND III, and all GM transmission specifications are going back to the year 2006.

Unfortunately, there is one thing I hate to tell you about this reliable ATF. If you are a proud owner of any CVT or DCT vehicle, this fluid does not work for you. You’ll have to watch the celebrations from the sidelines.

Note: Some users noticed that the oil had changed color after a few miles, say 1000. As a mechanic, I don’t think this should be your biggest worry as long as your transmission performs well. Just keep up with your regular maintenance. Trust me! You will be fine.

Verdict

It is one of the most popular and cost-effective products with excellent compatibility and professional grade. If your car uses the same brand’s previous version, the ACDelco 10-9395 Dexon VI can be an improved replacement.  

Best for wide range alternative cars: Valvoline DEXRON VI/MERCON LV

Another new kid in town is the Valvoline DEXRON VI/MERCON LV (ATF) Full Synthetic Automatic Transmission Fluid 1 QT, a must-have for automatic car owners. This fluid will amaze you with its resistance to high-temperature fatigue that cuts out many engine transmissions for starters. It protects your gearbox from rust and sludge formation, making it receptive to gear changes. You will experience smooth driving without any gear locks, burning, or rejection at high speed with less friction.

One thing you should not forget is that having this fluid improves transmission durability, enabling you to drive for longer without any changes. Equally, you will have a silent engine without the noisy croaking sounds. Now, this may surprise you as it did to me. This ATF is versatile and has worked well for me in both cold and high heat temperatures. Secret? Your engine does not shiver in cold winters and also does not overheat in the hot summer.

Sadly, I noticed it as my friend has issues with his GM 2500 truck, as this ATF is not compatible with his specifications. Besides that, most of those with compatible DEVRON II, III, and VI cars need some good cash to have this fluid. I thought you should know that and make your considerations.

Verdict

This product boasts some excellent features that make it great for common issues of rough and grinding gears, sludge accumulation, and varnish build-up. 

Best for High Mileage Numbers: Castrol 03520C TRANSMAX DEX/MERC

The Castrol ATF works to enhance antifriction durability to allow your driving to be as smooth as possible. With a wide compatibility range, it will give service to any of the Dexron models from III, II, and HE specifications. Additionally, I love the fact that it works well on Mercon requirements. Older GM and Ford models and a few Japanese importations fall in this specification bracket.

Unlike most TFs, this one comes in significantly large size bottles for your requirements. Check and confirm your model’s compatibility before topping up with Castrol 03520C ATF. Coming in as a surprise is you can use Castrol on your power steering needs in Mercon models. So drive away with superior viscosity and have less corrosion and rusty gearboxes for a smooth trip and power steering.

While there is nothing secret about this ATF, one thing is good to note. The label signifies that it is for domestic models, and that may not be true. My neighbor’s 2007 Nissan Altima works well on it, and so do several other Japanese models. So before heading for that seemingly compatible aftermarket product, have a look at your foreign model specifications.

Verdict

If your automatic transmission is designed for Mercon and Dexron lubricants, the Castrol 03520C TRANSMAX DEX/MERC ATF is recommended. The product ensures smooth shifting performance with its enhanced friction durability.

Best CVTs transmission fluids 

Best for frequent changing – Castrol 15B652-6PK Transmax Black

One of the best things I love about Castrol Transmax CVT is that it uses smooth drive technology and provides a swift driving experience. The product is intended for vehicles that most often need to change the transmission fluid. I loved how superior technology is utilized to enable longer transmission life.

After getting a new fluid, I am always concerned about chain slippage; the issue is also taken care of by including variator torque capacity to block the belt. Your vehicle will endure a “smoother for longer” experience with the Castrol Transmax CVT.

If you drive a Nissan, Toyota, Mitsubishi, Subaru, Daihatsu, Mazda, Suzuki, Hyundai, Chrysler, Mini Cooper, and Ford transportations, then this fluid is good enough.

One challenge I faced while changing the transmission was that the instructions are not clear in defining which cars should use it. However, as it gives improved corrosion security for higher transmission time, you can give it a try.

Note:

• We can you this lubricant for all Honda CTVs except 2001-2007 model Fit/Jazz (these trans are equipped with starting clutch).
• Even though this oil can be a good substitute for expensive OEM fluids, do not use this product if you are interested in preserving your warranty. The product can invalidate your warranty, especially if it is a Nissan drivetrain. 

Verdict

If you have a passenger car fitted with a push belt transmission, the Castrol – 15B652-6PK Transmax Black CVT can be suitable. It is a low-cost alternative for a wide range of CVT vehicles. The product also focuses on elongating your transmission’s life.  

Valvoline CVT full synthetic

This transmission fluid caught my attention because it is manufactured for maximum efficiency, increasing the longevity of your transmission arrangement. The lubricant features multi-viscosity grades. So if you want maximum protection of your transmission system in all types of weather, this one’s for you.

What impressed me the most is how this exceptional synthetic transmission fluid provides an excellent wet clutch for the best smooth drive ever. The fluid comes with a wear-out formulation, so this fluid will keep your transmission system working for a long period.

What makes Valvoline CVT Full Synthetic losing the rank is that it does not reach the MERCON LV designation, so if you require one with this specification, sadly this one is not for you. Moreover, it owns Toyota and Ford hybrids then it is not for you as Valvoline CVT Full Synthetic does not support these variants.

One more problem with this product is its odor. The first time I got this fluid and opened it. Omg! my nose begged for mercy. The scent is strong and can be unpleasant. So, watch out if you are sensitive to strong smells. Note that this does not overrule the fact many customers found the CTV fluid very helpful. 

Note: Do not use this lubricant for Toyota or Ford Hybrid.

Verdict

The fluid is less expensive than many OEM oils and can be used as a replacement in lots of chain and belt-driven CVTs.  

Nissan Genuine OEM CVT-2

The top product that impressed me is the latest formula anti-wear. If you are concerned about the sustainability of your transmission system, this fluid is for you as it keeps the transmission system working for a long period.

The high temperature always made me worry about changing the fluid; however, I noticed that it gives excellent execution even under soaring heat using this transmission fluid.

After using Nissan Genuine OEM CVT-2, your transmission system will stay in complete protection from thermal distortions. Also, I loved the fact that it includes the synthetic formula.

One more feature that makes this transmission fluid stand out is that it is formed to shield your transmission regularity from thermic falsifications.

However, one of the biggest concerns I encounter is that the transmission fluid needs absolute accuracy while using in your car. If a measured quantity is not used it can make your car defective.

Verdict

The CVT fluid boasts unique friction and additive modifiers and will be a good buy if you drive a Nissan and Infiniti. However, you may have to look somewhere else if you ride something different.  

Best manual transmission fluid 

Red Line 50304 MT-90 75W-90 GL-4

The first good thing is Red Line transmission fluid ensures smooth gliding gear shifting, which protects your car parts from regular friction. I like the low non-reactive sulfur content that does not react to corrode the gearbox parts. A deserving feature of this MTF is its friction reduction to give your car parts durability.

Significantly, if your car models fluid requirements lie in SAE 15W40, 10w40 to 40, this transmission oil will be a perfect match. Additional models with oil requirements compatible with 90, 80W90, and 75W90 can maximize their gear parts’ longevity by using this fluid. Experts recommend this fluid for car models under GL requirements 1, 3, and 4. I love it most because this Red Line MTF can help avoid the unnecessary clashing of gearbox dog teeth for owners of synchromesh models.

Well, every rose flower has thorns, and so does this product. One thing about this MTF that always catches my eye is its performance on cold days. As a lover of this MTF, I have to admit that all is well until you hit the sub-zero days. From my experience with the 2000 Mazda Miata SE, this transmission fluid can lag on cold days unless you have time to warm up the engine.

Verdict

This is the best choice if your vehicle is compatible with GL-4 and the manual transmission comes with brass synchros (yellow metals). Also, it is helpful if you are experiencing barely moving, rough, and grinding shifts. 

Genuine Honda fluid 08798-9031 

This MTF is arguably the best in the market for Honda car engines. To start, the Honda Fluid 08798-9031 MTF makes it easy to shift gears without any cranking noise in the gearbox, leaving you to enjoy long mile driving without any wear and friction. Another feature to celebrate is the ability to lower fluid friction giving gear levers smooth and non-corrosive edges. 

This MTF viscosity is suitable for any car with needs in the range of 10W-30 oil to 75W. With expert recommendations, anyone with a GL 3 engine specification can opt for this MTF to lower abrasion on the manual gearbox brass parts. 

One thing that stays in my heart about this fluid is the ability to work as a substitute for all Honda models for a 30K mile drive without adverse effects. My personal experience with a friend’s 1992 Honda Civic D15B7 is a testimony that this stuff is good for silencing the gearbox noises and improving highway cruising. So, prepare for a long-term relationship with your car, as no one is getting old any sooner.

One sad observation about this MTF is that you have to cough up some cash for its high price. As most models under this 10W-30 to 75W need 2 to 2.5 quarts of fluid, this MTF packaging comes in 1 quart, and yet still more expensive than most alternatives. Well, there is always a price if you are looking for a spouse in life, isn’t it?

Verdict

The product is an inexpensive MTF that offers a reduced friction level compared to other similarly priced fluids. The best original MTF product to buy if you have some cash for a stable gearbox.

 Valvoline Synchromesh 

This synchromesh MTF provides for fluid shifting of gears with better gear teeth lubrication to reduce the traditional brass parts friction. One noticeable advantage is the efficient performance in both cold and hot temperatures, making it a better option than the MT-90 oils. It is good to know that some guys experiment and claim better transmission results after mixing Valvoline MTF and Redline MT-90 (not advisable at all, though).

If you fear viscosity changes, you are safe with Valvoline Synchromesh MTF. The fluid modifier stabilizes the index to work well with bronze and copper parts. Better lubrication protects your car in manual transaxles and fluid transmissions. Then keep your car away from metal chips in the piping with a less foaming MTF for longer driving on the road.

For a better improvement, you need to understand this significant consideration. The Valvoline MTF seems to offer better performance on GM Chrysler modern models. So if you have older Toyota cars similar to specs 75W-90 gearboxes, this may not make your day better on the road, more so on the highway speeds.

FAQs

1. Is it wrong to mix transmission fluid brands? 

You can mix different brands of transmission fluids. However, ensure the oils you are mixing meet your vehicle’s requirements. Otherwise, you are begging for trouble. In this case, avoid going for “works with all imports” products. Additionally, although product upgrades like DEXRON-VI are designed to be backward compatible, earlier fluid types are not forward compatible with transmissions designed to use upgraded oil types.    

2. Is full synthetic transmission fluid better? 

Yes, full synthetic transmission oil is better. It formulated to last longer and provide overall engine protection and performance than conventional types. Additionally, it ensures you go longer between fluid changes without sacrificing the lubrication’s quality. Synthetic uses high-quality base oils and is specially formulated with a tailored additive system that provides more benefits than synthetic and conventional blend oils. 

3. Does transmission fluid brand matter?

The transmission oil brand does not matter much. However, transmission fluid type absolutely does matter. For example, you can’t use ATF4 where Dex3/Mercron is required. But you can use different brands as long as they are reliable, high-quality, and meets your vehicle’s TF requirements. One of the few situations where brands matter is when your vehicle is still under warranty. Using unapproved fluid for some cars can void their warranty.

4. What’s the difference between ATF and CVT fluid?    

The automatic transmission uses fluid coupling instead of a friction clutch. So, it needs ATF for lubrication and to reduce friction during gear changes when your car is running. On the other hand, the continuously variable transmission (CVT) has a belt-driven design that runs on the pulley system. It needs more friction to prevent the belt from slipping on the pulley system, and that is where CVT fluid comes into play. To cut the story short, ATF reduces friction while CVT fluid increases friction in transmission systems. 

Final thought

When selecting a fluid for your transmission, several factors like the formulation and viscosity should be considered to avoid transmission damage. So, which is the best fluid for your automatic, manual, or CVT transmission? The simplest solution to picking the correct and suitable oil is to check your vehicle owner’s manual. It will show you the exact fluid to use and the GL and Viscosity value specific to your car.