All car owners need to have a great transmission fluid for many reasons. You use them for lubrication, to maintain the appropriate pressure, and to cool your vehicle’s transmission. Whether you own a vehicle with a manual or an automatic transmission, you need the best transmission fluid to keep everything running smoothly.
It’s very important to change your transmission fluid regularly. Otherwise, the fluid you’ve used will start losing its efficiency over time. This happens because of prolonged heating and because of contaminates. Read on to learn more about how to choose the right transmission fluid for your needs.
- Features to Consider in Good Transmission Fluids
- Top 10 Best Transmission Fluids 2024
- 1. Red Line (50304) Manual Transmission Fluid
- 2. Red Line 30504 D4 Automatic Transmission Fluid
- 3. Honda Genuine Fluid 08798-9031 Manual Transmission Fluid
- 4. Royal Purple 01320 Max Automatic Transmission Fluid
- 5. ACDelco 10-9395 Dexron VI Automatic Transmission Fluid
- 6. Castrol 03520C TRANSMAX DEX/MERC ATF
- 7. Genuine Ford Fluid XT-M5-QS Synthetic Manual Transmission Fluid
- 8. Mobil 1 112980 Synthetic Automatic Transmission Fluid
- 9. Valvoline MaxLife Synthetic Automatic Transmission Fluid
- 10. Castrol 03518 Transmax ATF Green Transmission Fluid
- Guide to Buying the Best Transmission Fluids
- The Verdict
Features to Consider in Good Transmission Fluids
There are two main types of vehicle transmissions, and they both need regular servicing which involves the replacement of gasket and transmission fluid replacement. This will provide you with smoother gear changes, improve the efficiency of your transmission, and more.
Automatic
Automatic transmission fluids or ATFs will provide your vehicle with anti-rust, cooling, lubrication, and more qualities. Using this will prevent your transmission from overheating and producing debris. This, in turn, will maintain the quality and effectiveness of all the components inside of your transmission. Unlike manual transmission fluids, ATFs break down faster which means that you need to make fluid changes more frequently.
Manual
Manual transmissions are easier to maintain than the automatic ones. With such transmission, you can use manual transmission fluid, an ATF, a synthetic oil, and more. Also, you won’t need to change the fluid as frequently so you might want to choose a product which has a longer shelf life if you have manual transmission.
What should you look out for in a transmission fluid?
Compatibility
This is a very important feature to consider when searching for a transmission fluid. Some products have excellent compatibility which means that you can use it for different types of vehicles. If you own more than one vehicle or you plan to use the transmission fluid for different kinds of cars, then it’s best to choose a multi-vehicle product.
When choosing a product which claims to have compatibility with various models, you still need to practice caution. You should first make sure that your own vehicle’s transmission is also compatible with the product. Otherwise, the fluid might have an adverse effect on your transmission rather than improve it.
To find out the type of transmission fluid that’s compatible with your vehicle, check the owner’s manual. If you don’t have it, you can go online and check on the manufacturer’s website of your car. Knowing what transmission fluid to use will allow you to get the best performance out of your vehicle’s transmission.
Protective additives
Such products contain ingredients which can help with oxidation stability. The best transmission fluids on the market also include additives which can reduce foaming, prevent corrosion, and more. If a certain transmission fluid remains in your car’s transmission for a long time, it might start breaking down. This, in turn, causes a change in the viscosity and the fluid’s lubrication properties.
When this happens, it might cause problems in the operation, and it can also cause your transmission to fail. If you choose a product with protective additives, these may help improve your transmission. They may also provide protection to the transmission so you won’t have to change the fluid as frequently.
Conventional or synthetic
This is another feature to look out for, whether you need a conventional or a synthetic transmission fluid. Generally, synthetic fluids are more expensive, but they offer better performance. Also, it’s a lot more durable when used with higher temperatures. But with older car models, it’s better to choose a conventional fluid. This is especially true if you’ve never used a synthetic fluid on your transmission before.
Brand
As you search for a transmission fluid, you’ll find out that there are many brands available. All the biggest and most reputable brands in the automobile industry offer different types of transmission fluids. If you have the budget, you may choose a product from these brands.
But it’s important to note that many of the lesser-known brands also offer superior products. Usually, these even come at more affordable prices. The important part is to check the specifications of the product, and these may give you more information about its quality.
Price
Finally, check the price of the product too. But don’t base your choice only on the fluid’s cost. Purchasing the cheapest item available might even cause you to experience issues with your vehicle’s transmission. Find one which you think will suit your own vehicle but will also fit into your budget.
Top 10 Best Transmission Fluids 2024
1. Red Line (50304) Manual Transmission Fluid
Editor’s Rating:
Versatile
The Red Line (50304) MT-90 75W-90 GL-4 Manual Transmission Fluid is a versatile product which comes with a lot of benefits. Using this may provide your car with quicker shifts, better protection of the gears, and an enhanced coefficient of friction. Also, it works well with low and high-mileage vehicles. It’s quite popular with Mazda, Toyota, VW Audi, and Nissan models.
Superior performance
This product is one of the best transmission fluids on the market now thanks to its superior performance. It provides excellent performance even when you use it in situations where the temperature gets high and where cheaper, inferior transmission fluids tend to break down.
The Red Line (50304) MT-90 75W-90 GL-4 Manual Transmission Fluid has a distinct formula that’s low in sulfur making it compatible with synchronizers made of brass. It’s very useful in performance applications, and it also improves the cold shifting of vehicles. All these features make it one of the more popular products available.
Smoother movement
You can expect smoother movement from your vehicle when you use the Red Line (50304) MT-90 75W-90 GL-4 Manual Transmission Fluid. It’s a safe product that comes highly recommended by various automobile manufacturers. This transmission fluid should allow your manual transmission system to make quicker shifts and more efficient movements.
Pros
- It has a low-sulfur formulation making it compatible with synchronizers made of brass.
- When used in performance applications, it remains stable even if the temperature is high.
- It's also available with a lighter viscosity if that's what you need.
- It meets the viscosity requirements of gear oils and motor oils.
Cons
- It's one of the more expensive products on the market.
2. Red Line 30504 D4 Automatic Transmission Fluid
Editor’s Rating:
Formulation
The design of the Red Line 30504 D4 Automatic Transmission Fluid will provide enhanced thermal stability as well as a superior shiftability even at low temperatures compared to petroleum ATFs. This has a special formulation which offers a lower viscosity at low temperatures for faster shifting. It has balanced frictional properties which provide consistently smooth shifts.
Thermal stability
This ATF provides enhanced thermal stability to your vehicle. Also, using the Red Line 30504 D4 Automatic Transmission Fluid will allow you to enjoy superior shiftability even at low temperatures. Not only that, but it will also permit you to operate efficiently even when the temperatures are high.
With this ATF, you don’t have to varnish your valves or clutches which, in turn, helps prevent transmission failure. It offers an excellent stability over petroleum automatic transmission fluids. Even over longer drain intervals, you can still enjoy shifting that’s smoother and more consistent.
Better performance
The cold-temperature viscosity of this product is much lower, and this provides the improved shifting performance. The Red Line 30504 D4 Automatic Transmission Fluid also offers enhanced stability. With this product, you can give your vehicle better protection from varnishing while lengthening your transmission’s lifespan. All these features combined with a reasonable price makes it one of the best.
Pros
- Provides a superior shiftability when the temperature is low.
- Allows for operation even in high temperatures varnishing the clutches and valves.
- It provides you with a lower viscosity.
- Your car's shifting will become smoother and more consistent after using this transmission fluid.
Cons
- The fluid becomes darker in color quickly.
3. Honda Genuine Fluid 08798-9031 Manual Transmission Fluid
Editor’s Rating:
High-quality
This genuine transmission fluid from Honda is the exact OEM, or Original Equipment Manufacturer fluid vehicles normally come with. In choosing this product, you can enjoy its effectiveness, the superior quality, and the reputable brand. The Honda Genuine Fluid 08798-9031 Manual Transmission Fluid is one of the best available on the market now for manual transmissions.
It’s important to keep your investment protected, and you can do this by using this transmission fluid. This product has a brand new formulation, and you can use it for all Honda models. It offers improved fuel economy and shift quality and reduced fluid friction.
Good compatibility
This transmission fluid meets all the standard requirements for Honda vehicles. But this doesn’t mean that you can’t use it for other models. The Honda is the exact OEM, or Original Equipment Manufacturer has good compatibility because you can use it on any vehicle. It offers an increased performance level compared to similar transmission fluids within the same price range.
Affordable
Speaking of price, this manual transmission fluid is very affordable. The Honda is the exact OEM, or Original Equipment Manufacturer comes with a lot of great features without having a high price tag to match. Also, it provides a lower friction level compared to similar products. This transmission fluid even provides you with some improvement in the overall fuel economy of your vehicle.
Pros
- It's compatible with all types of Honda models.
- It has a new and improved formulation which meets the high-quality standards of Honda.
- Using this manual transmission may improve your vehicle's shift quality.
- It has a reduced fluid friction, and it offers enhanced fuel economy.
Cons
- Some customers claim that they don't see the difference or improvement.
4. Royal Purple 01320 Max Automatic Transmission Fluid
Editor’s Rating:
Efficient
This is a synthetic ATF which offers superior performance. It has a low friction coefficient and a high film strength which can reduce wear and heat dramatically. This is very important as it can help lengthen the life of your car’s transmission. Royal Purple 01320 Max Automatic Transmission Fluid also has improved oxidation stability compared to other products, and this gives it an extended fluid life.
Superb compatibility
This transmission fluid is scientifically-designed to give your vehicle’s transmission a longer life by reducing the wear and heat on the transmission system. For automatic transmissions, they tend to produce a lot of heat which means that they need a good transmission fluid for protection and cooling.
This is what the Royal Purple 01320 Max Automatic Transmission Fluid comes is best at which means that it can double the life of your transmission if you use it regularly. One excellent feature of this product is that it has excellent compatibility. You can even mix it with other ATF products. But for ultimate efficiency, flush out all your vehicle’s transmission fluid first then fill it with this synthetic product.
Oxidation stable
This is a premium fluid that has improved oxidation stability than other ATFs on the market now. This means that you can wait for a longer time before you need to change the fluid again. Using this product will help maintain the smooth operation of your transmission for a long period of time.
Pros
- It's a high-performance and high-quality automatic transmission fluid.
- The superior film strength reduces wear and heat dramatically.
- Has good compatibility and you can even mix it with other ATF products.
- It may extend the life of your vehicle's transmission.
Cons
- Some claim that they don't see any difference after using it.
5. ACDelco 10-9395 Dexron VI Automatic Transmission Fluid
Editor’s Rating:
Consistent performance
This is one of the best transmission fluids on the market because it will provide your vehicle’s shift with a consistent performance no matter what the condition is. It can help automatic transmissions perform better and last longer. The ACDelco 10-9395 Dexron VI Automatic Transmission Fluid is suitable for most vehicles, even for those which need specialized fluids.
Professional-grade
This is a professional-grade product that meets all the requirements of a safe and superior transmission fluid for automatic transmissions. It’s a high-quality product which will give you good value for the money you spend. The ACDelco 10-9395 Dexron VI Automatic Transmission Fluid comes at a reasonable price despite its efficiency and versatility.
Excellent compatibility
This ATF has backward compatibility with the previous versions of the same brand. This means that you can use the ACDelco 10-9395 Dexron VI Automatic Transmission Fluid as a replacement fluid for any older transmissions or vehicles. This ATF has a better oxidation resistance, foam control, friction durability, and more.
This product is fully licensed and approved by GM. It’s highly recommended for all types of GM models from 2006 and above. It’s also great for older vehicles even with its improved formulation. It’s one of the more cost-effective products available, and it’s also one of the most popular because of how compatible it is.
Pros
- It's one of the more affordable products available on the market.
- This product has backward compatibility with previous ATF products from DEXRON.
- It offers better performance over the previous transmission fluids from the same brand.
- It can improve fuel economy and lengthen the life of your transmission.
Cons
- It may lose its color quickly.
6. Castrol 03520C TRANSMAX DEX/MERC ATF
Editor’s Rating:
Superb compatibility
One of the best features of this automatic transmission fluid is its superb compatibility. You can use the Castrol 03520C TRANSMAX DEX/MERC ATF for all types of Ford models from 1983 all the way to 1996. Also, you can use it for General Motors from 2005 and all the earlier vehicles.
High-quality
This is a high-quality ATF which comes from one of the most well-known and reputable brands in the industry. Despite this, the Castrol 03520C TRANSMAX DEX/MERC ATF comes at an affordable price making it a popular choice among car owners. It meets all the requirements of DEXRON-III H and it satisfies all the requirements of DEXRON, DEXRON II, DEXRON IIE, and DEXRON III.
Efficient
This ATF will promote the improvement of the friction durability. This will give you a smoother experience when you’re changing gears. You can also use the Castrol 03520C TRANSMAX DEX/MERC ATF for many power steering applications which require MERCON. It’s engineered to improve the performance of your transmission while extending its life too.
This is a top-rated product which you can use for different vehicle models. You can even use this for power steering. It’s one of the best transmission fluids for the money because it offers superior value for each gallon compared to other products in the same price range.
Pros
- Improved friction durability to enhance the smoothness of your vehicle's transmission.
- It meets and satisfies the requirements of DEXRON, DEXRON-III, DEXRON-III H, DEXRON IIE, and DEXRON II.
- Also, it meets all the requirements and standards of its brand.
- You can also use this product for power steering applications.
Cons
- It's quite difficult to see the fluid level in the container.
7. Genuine Ford Fluid XT-M5-QS Synthetic Manual Transmission Fluid
Editor’s Rating:
High-quality
This is a high-quality manual transmission fluid that comes highly-recommended by Ford. It meets all the requirements of the company which ensures the consumers that they’re getting nothing but the best. It works best for IB5 and 1995 to 2011 MTX-75 transmissions. But it’s also recommended for older transmission models, even those which use GL-3 or GL-4 type oils for their gears.
Strong performance
The Genuine Ford Fluid XT-M5-QS Synthetic Manual Transmission Fluid will provide you with strong performance no matter what the temperature is. It also increases the efficiency of manual transmission systems. This fluid transmission meets all the requirements set by the Ford company for manual transmission systems. But you can use it for any vehicle.
It provides an excellent performance even for older transmission systems and vehicles with rear-wheel drive. Also, the synthetic fluid works efficiently in various environments. The transmission fluid has a wear protection which extends the life of your vehicle’s bearings and synchronizers. It even provides optimal lubrication which reduces friction and operating temperatures while improving the efficiency and component life.
Protects the transmission
It’s manufactured with performance additives and synthetic base oils to provide your vehicle with enhanced gear shifting at all temperatures. Because of the transmission fluid’s shear, oxidative, and thermal stability, it meets all the standard requirements. The Genuine Ford Fluid XT-M5-QS Synthetic Manual Transmission Fluid provides wear protection which will lengthen the life of bearings and synchronizers.
Pros
- Contains performance additives and synthetic base oils to enhance gear shifting.
- Comes with superior shear, oxidative, and thermal stability.
- It provides a wear protection to extend the life of your vehicle's bearings and synchronizers.
- Reduces friction to improve efficiency and component life.
Cons
- It's relatively expensive.
8. Mobil 1 112980 Synthetic Automatic Transmission Fluid
Editor’s Rating:
Superior performance
The Mobil 1 112980 Synthetic Automatic Transmission Fluid provides superior performance, and it can easily outperform conventional ATF products. It will help give your vehicle superior resistance to oil deposits and breakdown. This product comes with a viscosity stability and index that’s inherently high which helps protect against thermal breakdown which occurs while operating at high temperatures.
It also provides excellent performance at various temperatures, even those as low as -54˚ Celsius. It also helps enhance the overall cleanliness and durability of your car’s transmission. With this fluid, you can ensure the performance of your transmission as long as you use it on your vehicle regularly.
Premium quality
This premium quality transmission fluid has a velocity index of 176 which is relatively high compared to other standard products. It has an excellent flow even at cold temperatures. The Mobil 1 112980 Synthetic Automatic Transmission Fluid doesn’t break down easily even at high temperatures and may contribute to smoother shifting and cooler operation.
Versatile
The Mobil 1 112980 Synthetic Automatic Transmission Fluid is perfect for those who live in areas with a cold climate as it will still provide superior performance. This ATF works with different types of vehicles from GM, Ford, and most of the domestic models. It’s an excellent product that’s fully synthetic, and it promotes smooth and cool operation.
Pros
- Helps extend and improve the efficiency of your transmission.
- It will keep your transmission clean even under severe conditions.
- It offers superior wear protection to enhance the longevity of your transmission.
- Provides you with reliable and prompt lubrication for your vehicle.
Cons
- Not suitable for Dexron 4 vehicles.
9. Valvoline MaxLife Synthetic Automatic Transmission Fluid
Editor’s Rating:
Full formulation
This ATF has a full synthetic formula, and it even contains advanced additives. These help prevent the main causes of the breakdown of a transmission, therefore, helping to extend its life. The Valvoline MaxLife Synthetic Automatic Transmission Fluid can help maximize the performance of your car’s transmission, it can help reduce wear, prevent leaks, and even maintain the smoothness of shifting.
Refined
The Valvoline MaxLife Synthetic Automatic Transmission Fluid has paraffinic oil as its base. It also has an additive package that’s extremely refined making this product suitable for almost all types of modern applications of automatic transmissions. Since it’s a synthetic fluid, it also boasts a longer drain interval.
Aside from having good compatibility with transmission seals, this product contains special additives including an agent which conditions the seals for the prevention of leaks. It also contains some cleaning agents which can eliminate deposits from components which are friction-prone. Some of the additives even discourage the accumulation of deposits to keep your transmission clean.
High-quality
This high-quality transmission fluid exceeds the specs of its manufacturer more than the competition. It’s compatible with Mercon V, Mercon LV, Dexron VI, and more. It also works with most European models including BMW, Saab, Audi, and Mercedes-Benz. It’s made with base oils which are fully-synthetic to provide enhanced thermal properties compared to conventional oils.
Pros
- It's made with a full, synthetic formula with advanced additives which may help extend the life of your transmission.
- The base oils in this product are fully synthetic to provide you with better thermal properties.
- Along with its additives, it also contains cleaning agents.
- It's ideal for Mercon LV, Dex/Merc, and a lot of other specs.
Cons
- Not suitable for dual-clutch or CVT transmissions.
10. Castrol 03518 Transmax ATF Green Transmission Fluid
Editor’s Rating:
Efficient
The Castrol 03518 Transmax ATF Green Transmission Fluid is an excellent product for those who want to find a solution to the common problems of transmissions. It has an improved frictional durability, and it also contains added seal conditioners. This transmission fluid even contains additional cleaning agents which can help reduce the formation of sludge and varnish. It will protect your vehicle’s clutch from wear, and it brings back smooth shifting.
Extra components
This ATF can help reduce leaks and restore smooth shifts, some common issues of tired and worn-out transmissions. The Castrol 03518 Transmax ATF Green Transmission Fluid contains extra seal conditioners and cleaning agents. It even has improved frictional durability making it better than other products on the market.
This product is one of the best transmission fluids especially for vehicles with a high mileage. It meets all the requirements of General Motors, Ford, MERCON, and DEXRON-IIIH. The transmission fluid helps reduce the formation of sludge and varnish while protecting the clutch against wear. It promotes smooth shifting and provides superior performance for your car’s transmission.
Exceeds the standards
As time goes by, the transmission clocks up more and more miles. Therefore, the fluid you use to reflect your car’s condition is crucial. The Castrol 03518 Transmax ATF Green Transmission Fluid is perfect for vehicles with a high mileage, those whose transmissions have already covered more than 75,000 miles. This product meets and even exceeds the requirements of different companies and vehicular warranty requirements.
Pros
- Includes seal conditioners which may prevent leaks.
- Contains added cleaning agents to reduce the formulation of sludge and varnish.
- May help restore smooth shifting and protect the clutch from wear.
- Increased frictional durability to provide you with excellent transmission performance.
Cons
- Some customers don't appreciate the smell of the product.
Guide to Buying the Best Transmission Fluids
These are the top transmission fluids available on the market now. They’re meant for different types of vehicles, and they come with different features. Read the specs carefully, and this will help you determine which one is the best transmission fluid for your car. Also, there are some factors to consider which will help you making a better choice.
Automatic or manual
In the previous section, we talked about manual and automatic transmission fluids. Now let’s discuss manual and automatic transmissions. Either of these can be very enjoyable to use unless there’s a problem with your shifting capabilities. If you have manual transmission, choose a product which can help lubricate your gear sets and synchronizers. This will allow for smoother shifting.
If you have an automatic transmission, then choose a good ATF. This would allow your transmission to work effectively under various operating temperatures. But over time, the ATF may start breaking down which would cause your transmission to gradually shift gears. When this happens, you need to change the filter as well as the fluid.
Formulation
There are different types and varieties of transmission fluids, and they all come with varying formulations. These products differ in frictional properties, viscosity, additives, and other relevant factors. Manufacturers may make changes in the formulation of their products once in a while after introducing them. These changes are very common which is why you have to take the recommendations of the manufacturer seriously.
Transmission fluids are either conventional or mineral-oil-based. The latter is the synthetic variety and is generally derived from conventional-based oils then synthesized to suit the requirements of automatic transmissions. Check the formulation of the product carefully and make sure it has good compatibility with your own vehicle.
Frictional properties
This is another important factor for you to consider. Transmission fluids, whether manual or automatic, have different frictional properties. Transmissions have different designs, and they require various friction materials. Because of this, the fluid you choose should be able to work alongside these materials to prevent excessive chatter or slipping.
The problem is that automatic transmissions these days are becoming more complicated. There are people who find it better than automatic and therefore it is always in demand. Therefore, you would need specific types of fluids to keep them running efficiently. No matter what vehicle model you have, it’s important to know what frictional properties the transmission requires so you can choose the right product.
What are the most important specifications to look out for when choosing a transmission fluid?
If you don’t know what you’re looking for, finding the best transmission fluid for your car can be a very laborious task. Vehicle manufacturers have their own individual specs for the transmissions of their car models. If you use a fluid that doesn’t work with your car’s transmission, you might run into unnecessary problems such as erratic shifting, wear, and more. Therefore, when selecting, consider these very important factors:
Viscosity
This factor alone can be a huge issue on its own. If you use a fuel with the wrong viscosity, then it may lead to a complete failure of your transmission. So, check the viscosity of the product against the requirements of your vehicle.
Type
The type of fluid is also crucial as this can have an impact on the performance level and the life of your car’s transmission. Make sure that the product you choose meets all the specification requirements of your vehicle. You can find all the specification information and recommendations in the owner’s manual of your car.
The Verdict
Whether you own a vehicle with a manual or an automatic transmission, you need a good transmission fluid to avoid problems with shifting gears. Changing your vehicle’s transmission fluid is important for specific components to work smoothly. If you want to have an excellent driving experience, then you need to find for yourself the best transmission fluid on the market now.
Such products have important functions for vehicles which is why you need to choose the right one. In this article, we’ve reviewed the best products available, making your choice much easier. We’ve also provided you with a buying guide to help you determine which product would be ideal for your own vehicle.
