Top 12 Best Transmission Additives Review In 2021

There could be a lot of issues your vehicle may face due to lack of proper transmission fluid. It is difficult to judge the quality of the transmission fluid unless you use it. Fortunately, you can add a transmission additive to the fluid to address the common issues such as lowering friction and heat, protecting gears and bearing, and much more. They can restore the expected properties of the best transmission additives and let your vehicle perform at its best. But what actually is that?

List of The Best Transmission Additives

Last update on 2021-12-06 at 13:35 (UTC+0) / Affiliate links / Images from Amazon Product Advertising API

What Is Transmission Additive?

The transmission system is one of the most crucial parts of your vehicle. It works in association with your vehicle’s engine, and it determines the performance of your vehicle at different speeds. Just like the engine needs motor oil, the transmission system needs transmission fluid for lubrication. With proper lubrication and due to lack of treatment of the transmission fluid, the transmission system will get overheated due to friction and the performance of the vehicle will gradually go down. If the situation continues, the transmission system will stop working and repairing will lead to spending thousands of dollars.

Therefore, it is always recommended to treat the transmission fluid with a transmission additive to avoid various issues that are commonly associated with the transmission system of a vehicle. A transmission additive can minimize small transmission fluid leaks that are very common. Leaks can make the transmission system inefficient. Since a transmission fluid is corrosive, leaks can lead to significant problems in the various parts. Therefore, you need to treat the transmission fluid with a transmission additive.

The following contains the best transmission additives from which you can choose one for your vehicle’s peak performance.

#12. Lucas Transmission Fix

Lucas 10009 Transmission Fix 24 oz. by AI

  Get it now on

By: AI

For its amazing performance, this transmission additive is highly recommended, even though it is relatively new in the market. It will extend the life of your transmission and ensure that there will be no problems when you drive. Moreover, it has no solvents and will not cause any harm to the metal surface. This will lower the operating temperature and is also effective in controlling foaming.

You can easily add this to your fluid without having draining it out. Furthermore, the product will also take care of slip, and there will be no hard shifting. Another quality of this additive is that it will stop the leaks and will extend the life of your transmission. This comes in a size of 24oz and is a quick transmission fix.

#11. Automatic Transmission Treatment

Microlon Automatic Transmission Treatment

  Get it now on

By: Microlon

A product which will assist you in giving smoother operation of your vehicle, this transmission additive will protect against scale and corrosion. It will reduce friction; it will also let you save money. Moreover, it will reduce the maintenance cost and is quick in bonding with the metal surface. With the usage of this product, it will give a microloan treatment to the metal.

Furthermore, it will not affect the fibrous surface and helps in proper operation. This contains superior cleaning agents with antioxidants and corrosion inhibitors. This will clean the imperfections as well as other deposits and will give a protective layer of coating on the metal. If you really want to increase the life of your transmission, then this is highly recommended.

#10. Oil For Rear End & Transmission

MACs Auto Parts 32-16020 Oil 600W - For Rear End & Transmission

  Get it now on

By: MACs Auto Parts

Suitable for application in various products, this transmission additive comes in the size of a quart bottle. This is an oil which can also be used on steering boxes and will ensure that the metal parts don’t get any harm. Furthermore, it is effective in motoring and is easier on brass and other soft metals. It seals your car and gives them better engineering.

Moreover, this does not contain any substances which can be harmful to your vehicle. It can be used in all types of vehicles and is also ideal to be applied to other products. This will not disappoint you when it comes to performance and has been in the market for over five decades. This is a lightweight lubricant which will take care of the worn seals.

#9. Auto Transmission Treatment

PolyDyn TX7 Auto Transmission Treatment

  Get it now on

By: PolyDyn TX7

With many amazing features, this one of the best transmission additives will prolong the life of your transmission. This is effective in providing you with a smoother and quieter shifting. Moreover, this will reduce the transmission wear and will also lower the transmission operating temperature. It will provide a soft seal and will ensure that your vehicle remains in a working condition.

This will reduce the friction and will take care of reducing the wear. Furthermore, it will make the transmission to operate cool and will also protect them against any poor circulation at the time of cold. During hot conditions, the additive will act against the thermal breakdown and will increase the life of the fluid. This is a value for money product and is highly recommended.

#8. Automatic Transmission Treatment

Cerma Automatic Transmission Treatment

  Get it now on

By: Cerma

Here is a useful fuel additive which will restore the performance of your automatic transmission. This is effective in fixing your transmission issues and will also stop the slippage. This will take care of the rough shifting and will also take care of the seal leaks. Furthermore, this will lower the operating temperature and is very suitable to be used in commercial vehicles.

Moreover, this will extend fluid life and is a perfect preventative product. The automatic transmission treatment will revitalize and will show its effect in just a single application. The transmission of your vehicle will get a protective coating which will ensure that it will last longer. This will also protect the planetary gears and goes with all types of vehicles.

#7. Pro-Seal Tranmission Additive Pack

Hapco Products - Pro-Seal

  Get it now on

By: Hapco Products Co.

Here is a powerful transmission additive which comes from a reputed brand. This is very gentle and does not have petroleum distillates. This will stop all types of leak in your transmission and can also be used on other parts like bearings, power steering units, rack, pinion, and differentials. Moreover, this will not harm the seals and is available in different packs.

Furthermore, this will restore the flexibility, and it will strengthen the rubber seals. It will also restore the elasticity and is the most concentrated leak sealant. This is guaranteed to give a permanent seal in your fluid system and does not have any solvents. This will improve the circulation of fluids and will allow your vehicle to drive normally.

#6. Automatic Transmission Kit

XADO Kit Automatic Transmission

  Get it now on


This automatic transmission additive will repair your car system, and it can be used for a variety of applications. This will give reliable protection to an automatic transmission, engine, and fuel system. Moreover, this will take care of the oil system and power steering booster. The very useful product will restore the main car systems and ensure that you drive without any problem.

Furthermore, it comes with anti-wear protection and is for complex treatment. This has an atomic metal conditioner and will prolong the life of your engine. This will rebuild the metal and reduce the friction. This will also rebuild the worn engine metal and give it a protective coating. This is also ideal for fuel injection system and can restore the power steering booster.

#5. Ford Powerstroke Best Stiction Stopper

Turbo Maxx Ford Powerstroke Best Stiction Stopper

  Get it now on

By: Turbo Maxx

With an ability to improve the engine condition, this transmission additive is effective in removing the carbon buildup and improving the MPG. This will also quiet the mechanical noises and will reduce the consumption of oil, thereby saving your money. This is very powerful and has many benefits. Furthermore, this will also improve the gear oil without any friction.

This is a friction fighter which will resist wear. Moreover, it can be used on all types of gas and diesel engine and can treat all types of manual transmissions. This will also improve the fuel mpg and will cool the oil temperature. You will be getting higher torque and will make your transmission last longer. Apart from the vehicle engine, you can also use it on a lawnmower engine.

#4. ATC Plus Tranmission


  Get it now on

By: BG

This is an automatic transmission conditioner which can be used on any type of automatic transmission. This will enhance their performance and improve with the fluid oxidation stability. The transmission additive will prevent the leak by conditioning the hardened seals and keep them soft. Furthermore, it will keep them pliable and keeps them in a working condition. All in all, it is one of the best transmission additives to opt for on the list.

Moreover, it will prolong fluid life and will extend the life of your transmission. With this, there will be no formation of shudder’s retards, and it will also prevent foaming. There will be no varnish deposits, and there will also be no fluid breakdown. This is very suitable for professional use and will assist you in the problems of shifting and shudder. The additive will ensure that there will be no transmission failure.

#3. Medic Automatic Transmission Treatment & Shift Improver

Niteo Motor Medic M3616-12PK Trans Medic Automatic Transmission Treatment & Shift Improver

  Get it now on

By: Niteo

Here is a transmission additive which will help in eliminating the slippage. It comes in two different sizes and will reduce the wear. Moreover, this will restore the smooth shifting and it also effective in quieting the excessive gear whine. You can conveniently add this to your ATF and experience a normal drive without even draining the fluid. This will not give you any trouble with regards to the transmission, and it will also reduce the shuddering.

This is a very useful product and can be used regularly. Furthermore, this will extend the life of your transmission, and you will witness a significant improvement from the first time to drive after using this. This will make the old transmission run like a new one. You can even use it if your transmission is working fine as it further makes it smoother. There will be no shifting problems and is effective in the treatment of your transmission. The highly recommended product will let you use your vehicle for years.

#2. Automatic & Manual Transmission Treatment

Prolong Super Lubricants PSL15000 Transmission Treatment

  Get it now on

By: Prolong Super Lubricants

This transmission additive comes with anti-friction metal treatment technology and is very suitable for treating metal surfaces. This is ideal in restoring the responsiveness in transmissions and also promotes smoother manual shifts. Moreover, this has molecules which are effective in interacting with metal surfaces and form a chemical bond in the creation of a protective layer. The product will also reduce the damaging friction as well as heat. With its chemical process, this treats both automatic transmissions and metal surfaces.

Furthermore, this is ultimate in performance and provide superior protection. Formulated with advanced technology, the product comes in a size of 8 ounces. When the gear oil circulates, this acts very well and reduces the chances of any damage from heat and friction. This can also be used in extreme pressure conditions and will give good protection. This is way economical than having an expensive repair. This will restore the responsiveness in your transmission even during critical acceleration conditions. It is clearly one of the best transmission additives to buy.

#1. Automatic Transmission Fluid Protectant

Lubegard 60902 Automatic Transmission Fluid Protectant

  Get it now on

By: Lubegard

If you are looking to prevent overheating and optimize the performance of your transmission, then this additive is highly recommended for you. This comes in various sizes and will also reduce the operating temperature. Moreover, this will eliminate the fluid foaming from your transmission and will modify the hard shifts in no time. This is very effective in softening the shifts, and there will also be no oxidation.

This will increase the ability of the fluid to transfer heat and will also protect the new seals. This will give permanent results in restoring the older seals, and there will be no adverse effects. Furthermore, this will also increase the life of the fluid as it makes it stable. This will fix all the shifting problems and protect the transmission. The concentrated additive will enhance the performance of your transmission and will not thin out or react with oxygen. This has anti-chatter, and there is also anti-shudder which has to be allowed for overnight penetration.

Transmission Additive — The Benefits

The following are the various benefits of using a transmission additive with transmission fluid.

  • Minimize Sludge: With time, the transmission fluids tend to get thick. There are various dirt and contaminants mix with it, and soon, sludge and varnish are formed. This will prevent the parts from moving smoothly. A transmission additive can prevent the formation and let your transmission fluid work the best.
  • Reduce Wearing: No matter how premium transmission fluid you use, as it starts to age, it gets thicker. The thicker it gets, the more friction begins to happen among parts in the transmission. A good transmission additive prevents that by keeping the transmission fluid soft and healthy. Therefore, it can keep up the excellent performance of the transmission and prevent wearing on parts. Consequently, you can save a lot in repairing, and it also reduces the noise and shudder generated.

Apart from that, it extends the lifetime of the transmission system, and let the vehicle operation at the peak of its performance indirectly.

How Does Transmission Additive Work?

Basically, your transmission needs fluid/additive to protect the gears and bearings from wear and tear. The transmission allows you to shift gears fluidly without strain, and it always works hard which is why additive is important. Some products even provide improvements in anti-shudder durability which increases the performance of the transmission which is great.

That is why you have to change the fluid once in a while to experience less transmission mechanical and component breakdown. You can either fully replace the fluid or just add the fluid to reduce the cost. The price range from $10 to above $20 depends on the brand and type of transmission additive that you choose.

Note: It is good to check your fluids at the 3,000 miles marl which is where most people get their oil changed. In case the ATF brand that you use is not so pricey, it is better to replace or add more regularly. That is better than ending up spending more on repairing when things go wrong. If you use your car frequently, a regular checkup is quite crucial.

Conventional Vs. Synthetic Transmission Additives

This is a very debatable topic since users prefer different types of transmission additives for their vehicles. In case you are new to this, the differences are:

  • Conventional: is ideal for some older car models. There are some car models that have been using conventional transmission additives since the beginning. So it is better to stick to this instead of changing it and experience unwanted issues.
  • Synthetic: is resistant to heat, cold, oxidation, sheer, and more. In fact, it is more durable at higher temperatures, so it provides better performance. Synthetic transmission fluids also tend to last longer as well which is why many people prefer using them.

Type Of Transmission Additives

There are 3 different types of transmission additives for vehicles which are:

  • Dexron III / Mercon: is one of the most common transmission additives. It works with most Fords, GMs, and imports with great quality and performance.
  • HFM-Style: is similar to the previous type, but it provides slightly different friction characteristics. In the market, HFM fluids also go under a few different names as well since imports also use it.
  • Type F: It was ideal for Fords with bronze clutches although this type is not common anymore. That is because modern vehicles no longer use bronze clutches since the 1970s.

Top Brands

In case you want to step up the game and go for famous brands of transmission fluids, here they are:

  • Castrol: is a global company that provides high quality automotive and industrial lubricants. Their products are top notch, and their business has been going on since 1899.
  • Pennzoil: has the base in Houston, Texas which is nearby. This brand has been creating innovative formulations for automative needs since 1913. It is an international oil company, and it is the big producer of motor oil, gear oil, and car transmission fluids.
  • Valvolin: has world headquarters in Lexington, Kentucky. This company has a big reach as it has been producing high-quality automotive lubricants and oils since 1866.


Sometimes, the problem may lie in the transmission system of the vehicle for poor performance. In such a case, one needs to repair or change the transmission system. But in most of the cases, the problem lies with the transmission fluid, and the additives are the way out. The properties of the best transmission additives we have listed above vary a lot. Therefore, you should carefully go through the product description and choose the one as per your requirements. They are the best in quality and will revive the original performance of the vehicles.

Leave a Comment