It’s easy to get lost in the transmission fluids jungle. There’s dozens and dozens of brands, types and sub-types of transmission fluids, also called “oils”. They evolved over time along with the gearbox technology. Some fluids are interchangeable, some aren’t. Some can be mixed, others can’t. Of all the fluids you have to periodically replace in your car, this is the most picky by far.
Though changing your car’s transmission fluid is a piece of cake and you’ll save a lot of money doing it yourself, it’s crucial to use the right fluid!
Get it right, and you’ll benefit from prolonged transmission life and smooth(er) shifting. Get it wrong and your gearbox won’t function properly and in the near future you may be looking at rebuild costs that can amount to thousands of dollars easily.
Each type of transmission fluid is formulated for use in specific gearboxes only. Their synthetic fluids and complicated additives packages make your transmission last longer and work better and smoother.
Although it’s nearly impossible to list all types of gearbox oils for every car out there, we made a “Best” selection for the majority of cars in the US.
Check out our selection of Best Transmission Fluids:
Best Multi-Vehicle Automatic Transmission Fluid | |
Best Mercon ULV Automatic Transmission Fluid | |
Best Mercon LV Automatic Transmission Fluid | |
Best Mercon or Mercon V Automatic Transmission Fluid | |
Best Mercon SP Automatic Transmission Fluid | |
Best Dexron HP Automatic Transmission Fluid | |
Best Dexron ULV Automatic Transmission Fluid | |
Best Dexron VI Automatic Transmission Fluid | |
Best Honda Automatic Transmission Fluid | |
Best ATF+4 Automatic Transmission Fluid | |
Best Multi-Vehicle Manual Transmission Fluid | |
Best CVT Transmission Fluid | |
Best DCT Transmission Fluid |
Transmission fluid serves a dual purpose:
You should change your transmission fluid within your car manufacturer’s recommended intervals (check owner’s manual) to keep your gearbox working as it should and to avoid premature wear.
Old transmission fluid degrades over time and with use. This causes your gearbox’s parts to overheat and wear quicker, leading to potentially high repair bills. By changing your gearbox oil in time, you will keep it running smoothly and avoid unnecessary costs.
You should change your transmission fluid according to your car manufacturer’s specifications. Check your service manual. Fluid change intervals differ widely between car brands and models. Some cars need more frequent transmission fluid changes than others. On average, car transmission fluids should be replaced every 30,000-60,000 miles. Some don’t need to be changed for the lifetime of the vehicle (about 150,000 miles).
However, even if your manual says it doesn’t need to be changed, it’s good practice to change the fluid at least every 100,000 miles to refresh the fluid and remove all the free-floating circulating metal shavings from normal wear. This will extend your gearbox’s life considerably.
Also, if you drive your vehicle hard, meaning towing, racing or mainly using it for short drives and city use (start/stop), you wanna replace your transmission fluid well before it is due. As a guideline, in these circumstances replace it twice as often as recommended by your vehicle’s manufacturer.
Whenever you notice erratic shifting behavior, strange whining noises or loss of traction with your engine performing seemingly normal, it’s a good idea to check your gearbox fluid.
First check for external tell-tale leaks. Your gearbox should be bone-dry. If it’s not, your transmission fluid level is probably too low. When you open the fill-hole, it should be filled to the point of overflowing, with a fresh translucent red color.
Check your vehicle’s manual for the right type of transmission fluid. Using the wrong fluid can cause mechanical malfunction, premature wear or breakdown resulting in expensive repair bills.
Before purchasing new transmission fluid, check for the exact type and abbreviations recommended in your owner’s manual (e.g.: Dexron VI, GL4, Mercon LV, Type F,…). Those exact names and abbreviations should be on the can or bottle.
Different types of transmissions need different types of fluids: Manual Transmission, “traditional” Automatic Transmission, DCT (Dual Clutch Transmission), CVT (Continuously Variable Transmission) to name the most popular.
Again, look for exactly what your vehicle’s manufacturer recommends. One character difference can mean a totally different fluid. E.g: Mercon LV (Low Viscosity) vs Mercon ULV (Ultra-Low Viscosity). These names may look similar, but these fluids are NOT interchangeable.
That said, there are some excellent smaller independent US-based brands out there that offer multi-vehicle transmission fluids that can be used in 99.9% of modern vehicles and outperform standard fluids. Some fine examples are Red Line and Royal Purple. Check their specs to make sure they can be used in your vehicle.
Only use high-quality premium fluids from renowned brands, don’t risk ruining one of the most expensive parts of your car. By saving a couple of bucks buying the cheapest fluid you can find, you risk paying thousands in repair bills in the near future.
How much transmission fluid your car or truck needs can vary widely, depending on your vehicle brand and type. Check your driver’s manual.
An average family car with auto transmission will need between 2 and 10 quarts of transmission fluid, an SUV with automatic transmission up to 17 quarts.
Generally, manual transmissions need much less fluid. Most EV’s only need up to 4 quarts of transmission fluid.
However, there’s a big difference between how much you need for a dry fill, a pan drop, a fluid flush or a top-up:
In any case, be careful not to overfill, because this can cause major mechanical damage!
For this review we dove deep in all manufacturer specifications and spent hours comparing and assessing customer reviews to see what people think about different products in different situations.
We also looked at what professionals have to say: transmission rebuilders, workshops,…
We only recommended transmission fluids that did an excellent job for the vast majority of car enthusiasts and professionals alike and filtered out unreliable sources. Armed with a critical eye and with our own experience under our belt, we connected the dots and selected the best products for each specific category.
Check out our favorite transmission fluids:
Royal Purple Max ATF is a long-life, high-performance, full-synthetic automatic transmission fluid. It exceeds performance and viscosity requirements of late model automatic transmission fluid specifications.
It can be used for a complete fluid change as well as a partial fluid change or top-offs, because it is compatible with OEM fluids.
Customer reviews rate it an incredible 4,8/5 and this premium ATF gets a thumbs-up from the pros too. They say it improves shifting and outperforms industry standard fluids.
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We chose this transmission fluid because it comes highly recommended by Ford owners and it is the standard OEM fluid used by professionals for ULV-type transmissions.
This ultra low viscosity gearbox fluid is extremely stable throughout its life, with less viscosity loss and improved low temperature performance. It protects against oxidation, rust and deposits. It was designed to eliminate transmission shudder as well.
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Between different competing Mercon LV transmission fluids, this one comes out on top because it provides best shift responsiveness under all conditions, cold or hot. It works great in electronically controlled automatic transmissions too.
Customers say it’s the best LV fluid on the market. Ford mechanics we consulted told us too: LV ‘boxes work best with Motorcraft juice.
Motorcraft Mercon LV provides excellent thermal, oxidation and shear stability and excellent low temperature performance. Not only does it inhibit the formation of gum, sludge, lacquer and foam, furthermore it provides superior wear protection. Also, rust and corrosion don’t stand a chance with this premium product!
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In all the Mercon and Mercon V transmission fluid tests and reviews, this premium full-synthetic ATF comes out on top. It is praised by customers for its affordability and durability. Test results conclude that this fluid noticeably improves shifting characteristics in the majority of cases and provides exceptional thermal protection.
Composed of advanced proprietary synthetic copolymers and highly refined base oils, it exceeds Ford’s requirements.
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Ford highly recommends Motorcraft Mercon SP for use in its Ford, Lincoln and Mercury vehicles. According to consumer reports, this transmission fluid also makes Jaguar and Hyundai cars equipped with transmissions that require Mercon SP shift smooth as silk.
Customer reviews state that even in the coldest winter temperatures, this fluid does an outstanding job.
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This affordable high quality product provides prompt and reliable lubrication at ambient temperatures down to -61º C. AK resident reviews state they only trust this brand for their 8-speed GM tranny. It’s equally well suited for hot climate use though.
It also performs exceptionally well in terms of shifting behavior and fuel economy.
Mobil 1 HP is a long-term solution that keeps your transmission clean, with excellent frictional properties to guarantee outstanding performance under severe conditions.
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We’ve selected Valvoline ULV ATF for “Best ULV ATF” because this full-synthetic, ultra-low viscosity transmission fluid has been uniquely engineered to meet and exceed General Motors’ and Ford’s latest 9- and 10-speed transmissions’ performance requirements. These smart gearboxes are extremely picky when it comes to fluid specs, and customers agree this is the safest choice.
Its advanced additive package reduces wear, maximizes performance and prevents leaks for much longer than conventional fluids.
It’s the #1 ULV ATF fluid on the market.
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The reason why we chose ACDelco GM OE DEXRON-VI Automatic Transmission Fluid is simple: with a whopping 4.8/5 score and a #1 DEXRON VI best-seller rating across the major websites, they must be doing something right!
According to thousands of customer reviews and professional workshops, you can’t find a better fluid to put in any transmission that requires DEXRON VI.
It’s backward compatible with previous Dexron automatic transmission fluids and can be used as a much-improved replacement, providing superior friction durability, viscosity stability, aeration and foam control, and oxidation resistance.
Most importantly, this upgrade can improve fuel economy, smoothen shifting, enhance performance and prolong your transmission’s life.
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The reason why we chose this ATF for “Best Honda Automatic Transmission Fluid” is that it is the only fluid that is approved by Honda for use in all of their trannys except for manual ones or CVT’s.
This unique Honda formulation contains specific additives to protect Honda seals and o-rings. This ATF makes your Honda transmission function smoother at high and low temperatures, providing maximum fuel efficiency. Its low oxidation rates allow for longer transmission fluid change intervals.
Customer reviews and Honda forums alike say to not take risks with your Honda transmission. They confirm that it needs this specific fluid to perform flawlessly for the longest time. The vast majority agrees that this is the only fluid to use in Honda trannys that require DW1 or Z1 ATF.
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The reason why we chose this MOPAR ATF+4 fluid for Chrysler, Ram, Dodge, Jeep and Plymouth vehicles is because it is the original OEM fluid that Chrysler (Stellantis) recommends. It was specially developed to provide the best lubrication under high load in all temperatures. This genuine MOPAR (Chrysler Motor Parts Corp.) ATF fluid can be used for all of the above-mentioned car brands that require ATF+4, ATF+3, ATF+2, or ATF+.
Customers say that when they replace their non-MOPAR fluid with this genuine ATF, they can really feel the difference. One customer says he tows his 13,000 lbs trailer with his V10 using this fluid and his tranny never gets hotter than 220°F, which is amazing! Aficionados say “MOPAR or NO CAR” for a reason…
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RED LINE MT-90 high-performance manual gearbox fluid has a large fan-base among demanding high-performance and off-road car owners alike (Nissan, Mazda, Mitsubishi, VW/Audi, Lotus Elise/Exige, Jeep, Toyota, Mendeola transmissions and Atlas transfer cases for off-road,…).
It’s less slippery for less gear noise and improved shifting. It also offers more consistent viscosity and a stronger film strength for wear protection in warm and cold temperatures. It’s 100% safe for yellow-metal/brass parts like synchros as it lacks the reactive sulfurs found in most GL-5 oils that cause damage.
MT-90 is a full-synthetic ester-based GL-4 lubricant designed specifically for use in High-Performance manual transmissions. It eliminates notchy shifting, even when cold, for high- and low-mile transmissions.
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The reason why we chose this CVT fluid is that it is safe to use in most vehicle transmissions that require CVT-spec fluid. Castrol Transmax® ATF/CVT Universal is formulated for both step-shifting and continuously variable automatic transmissions.
Castrol Transmax® ATF/CVT Universal is suitable for use in vehicles manufactured in North & South America, Europe, and Asia.
Its technologically advanced full-synthetic formulation is designed to deliver excellent performance under all conditions: cold, hot, normal and severe driving.
In all situations it provides enhanced friction durability for smooth transmission performance, superior high-temperature protection and unsurpassed protection against copper corrosion.
Here’s what customers say: “smoother drive, impressed”, “solved my CVT transmission slipping issues, awesome!”,…
For optimal fuel economy and butter-smooth shifting (well, power-transfer…) this is the best you can get. And, it’s very affordable!
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The reason why we chose this particular fluid is that Ford Dual Clutch transmissions arguably tend to be the pickiest of the bunch when it comes to their juices, especially in High Performance vehicles. This ATF is recommended by Ford and formulated to their exact specifications.
Our advice: don’t go experimenting with these complicated clutch systems, you’ll end up spending a lot more on repair bills if things go wrong. Although this DC fluid is expensive, it’s the stuff that works best.
It’s designed as a dual-functioning fluid to protect gears, synchronizers and bearings, while it is also used to operate the transmission’s shift mechanisms.
Although most customers would like a more affordable price tag, once they put this ATF in their ‘box, they report smoother shifts and better general performance.
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Brand | Name | |
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Best Multi-Vehicle Automatic Transmission Fluid | Royal Purple | Max ATF High Performance Synthetic Automatic Transmission Fluid |
Best Mercon ULV Automatic Transmission Fluid | Motorcraft | Mercon ULV Automatic Transmission Fluid |
Best Mercon LV Automatic Transmission Fluid | Motorcraft | Mercon LV Automatic Transmission Fluid |
Best Mercon or Mercon V Automatic Transmission Fluid | Castrol | Transmax Mercon V ATF |
Best Mercon SP Automatic Transmission Fluid | Motorcraft | Genuine Ford Fluid MERCON SP Automatic Transmission Fluid |
Best Dexron HP Automatic Transmission Fluid | Mobil 1 | Synthetic LV ATF HP |
Best Dexron ULV Automatic Transmission Fluid | Valvoline | ULV Transmission Fluid |
Best Dexron VI Automatic Transmission Fluid | ACDelco | GM Original Equipment Dexron VI Automatic Transmission Fluid |
Best Honda Automatic Transmission Fluid | Honda Genuine | ATF DW-1 Automatic Transmission Fluid |
Best ATF+4 Automatic Transmission Fluid | Mopar | Genuine Chrysler Accessories ATF+4 Automatic Transmission Fluid |
Best Multi-Vehicle Manual Transmission Fluid | Red Line | 75W-90 GL-4 Manual Transmission |
Best CVT Transmission Fluid | Castrol | Transmax CVT Transmission Fluid |
Best DCT Transmission Fluid | Motorcraft | Dual Clutch Transmission (DCT) Fluid |
Each type of transmission fluid is formulated for use in specific gearboxes only. Their synthetic fluids and complicated additives packages make your transmission last longer and work better and smoother.
It’s good practice to replace your transmission fluid every 30,000-60,000 miles. No special tools are needed and anyone can do it. It only takes one hour max and you’ll save a lot of money in the process.
It’s easy to get lost in the transmission fluids jungle though. There’s so many brands and types of transmission fluids, it’s easy to get it wrong. Some fluids are interchangeable, some aren’t. Some can be mixed, others can’t. Of all the fluids you have to periodically replace in your car, this is the most picky by far.
Although it’s nearly impossible to list all types of gearbox oils for every car out there, we made a “Best” selection for the majority of cars in the US.
Armed with our “Best” selection and some elbow grease, you’re set for success!
On average, car transmission fluids should be replaced every 30,000-60,000 miles.
However, car transmission fluid change intervals can widely vary between car brands and types. Check your car manual and always follow your car manufacturer’s recommendations.
As a general rule you should change your transmission fluid more often if your car is driven “severely”. This means if your car or truck is used for towing, racing or is used mainly for short drives and in heavy city traffic (start/stop).
These “severe” conditions put much more strain on your gearbox and its fluid. Your transmission fluid will degrade and break down much faster and gradually lose its much needed lubricating and cooling properties. This in turn will lead to increasingly faster gear wear, higher operating temperatures and even faster deterioration of the transmission fluid as a consequence. It’s a downward spiral leading to increased gearbox wear and eventually catastrophic failure and huge repair bills.
In any case, it’s smart to do a transmission fluid change before it’s due. A transmission fluid swap only costs a fraction of a gearbox rebuild!
No, you can’t.
If you drive your vehicle when your transmission fluid level is low, your gearbox will overheat due to poor lubrication. This can cause irreversible mechanical damage.
Depending on how low the fluid level is, your transmission will age prematurely and cause your transmission to function and shift erratically. Low transmission fluid can cause catastrophic failure, putting you and your passengers in harm’s way.
Frank is a true DIYer and car enthusiast with over three decades of hands-on experience. He's mastered everything from classic car restoration and detailing to drafting renovation blueprints and construction. With a penchant for tools and home improvement, he's constantly enhancing his house and garden. In his garage, his passions merge as he meticulously maintains and refines his beloved cars. Seeking to channel his vast DIY knowledge and professional experience in product analysis and trade, he founded this site. Offering readers invaluable insights to maximize value and achieve project success, Frank ensures you get the real deal in a world full of hyped-up products and sneaky paid promos.
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