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What is the Best Automatic Transmission Fluid?

Winter diesel bus in Philadelphia.

Today, modern vehicles have a choice between lubricants that are considered conventional or custom blended synthetic lubricants. When deciding what is the best automatic transmission fluid, the first step in answering this question is to look at the base oils used for both conventional automatic transmission fluids and synthetic-based automatic transmission fluids.

Conventional automatic transmission fluids that are created with conventional base oils exhibit compromised performance. The molecular structure of these base oils show the molecules to be of different sizes and uneven. Such a molecular structure inherently causes the oil to flow with excessive friction. Friction generates heat, so over time, this fluid friction can slowly degrade the oil. This is before we consider heat generated in an automatic transmission during use and also the pressure and friction caused between the moving metal components. An automatic transmission is a complex system that must be kept clean so that it can perform efficiently. Ordinary conventional base oils tend to break down when exposed to heat and mechanical movements. These oils, when exposed to excessive heat, start to oxidize. When this happens, unwanted deposits such as gum and varnish start to accumulate within the precise and sensitive components inside an automatic transmission. The transmission starts to slip and perform inefficiently. When this happens, it is time to bring the vehicle to the repair shop and change the fluid. Filters have most likely become clogged with sludge deposits, and wear metals, all due to inadequate lubrication.

An automatic transmission fluid engineered to be long lasting, resistant to heat and oxidation, and effective in cold and hot temperatures, is a lubricant designed utilizing specialized synthetic base oils. The choice by the lubricant manufacturer in using synthetic base oils is one based on the technical superiority of such an oil. First, the molecular structure is even and perfect. It offers minimal fluid friction, flows extremely easily in cold weather and start ups, plus it is devoid of any unwanted byproducts. There are other beneficial reasons to incorporate synthetic base oils into a custom blended automatic transmission fluid. It offers compatibility with petroleum oils, as well as other types of synthetic transmission fluids. Such an oil offers compatibility with gaskets, seals, and varying types of transmission components. Even before the base oil is enhanced with additives, it offers naturally long service life.

Fleet of school buses.
A synthetic-based automatic transmission fluid will outperform conventional ATF fluids in all important parameters, such as cold weather, hot weather, etc.

 

 

 

 

 

 

Though there is no such thing as one automatic transmission fluid for all applications, a custom blended synthetic ATF fluid will be useful in a vast range of automatic transmissions. It’s about as close as you will find to a universal fluid. Another reason that will help determine what is the best automatic transmission fluid would be the quality of the chemistry and the performance engineered into such a formulation. The ultimate goal is to design an ATF fluid that can resist oxidation, foam, leakage, wear, corrosion, and rust. Also, ideally you would want such a fluid to easily handle cold weather and also offer long service life. Yes, this is a tall order for most conventional transmission fluids. Still, there are specialty lubricant manufacturers that exist to create lubricating oils that actually solve problems and deliver real benefits. Of course, this philosophy is quite different from conventional fluids. The chemists from these specialty companies never consider the cost of making a product, their main goal is outright performance. In the case of automatic transmission fluids, such a strategy can pay real dividends. Ultimately, the cheapest product will inevitably be the most costly due to premature failure of the system.

To build a high-performance automatic transmission fluid that can find use in a wide range of vehicles does require a vast understanding of chemistry and mechanical know-how. For sure, there are a few multi-vehicle synthetic automatic transmission fluids that are blended with synthetic base oils along with a robust additive chemistry. They deliver a lubricant that will radically reduce wear, eliminate corrosion and rust, stop oil leakage, control foam, is totally resistant to oxidation, offers superior cold weather performance, and lastly, offers long and extended service life.

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A highly engineered custom blended synthetic ATF will be useful in a wide array of vehicles. It will deliver superior protection against wear, oxidation, and eliminate sludge and varnish.

 

 

 

 

 

 

 

 

Since these transmissions are called automatic transmissions and shift precisely on their own, the goal would be to preserve and protect the quality of the shifting and the shift times. Here is another performance area that will give better insight into what is the best automatic transmission fluid. To be able to protect the original equipment manufacturer’s settings for shift quality and shift times requires a custom blended automatic transmission fluid formulated with unique friction modifiers. Maintaining shift quality and smoothness that is acceptable to the driver requires specialized high-performance additives that help protect long term the durability and quality of the shifting of the transmission. Choosing the right transmission fluid so that the process is preserved long term will be a critical choice for your vehicle and equipment.

One other area where a fluid can help is preserving the transmission’s anti-shutter performance capabilities. Again, an engineered synthetic based ATF fluid will already have considered the preservation of this anti-shutter characteristic of the transmission. Anti-shutter is very important for the following types of vehicles, such as transit buses, school buses, emergency vehicles, motor homes, and of course regular automobiles.

Small yellow school bus.
Preserving anti-shutter characteristics is critical for transit type vehicles. Making synthetic-based ATF fluids part of your fleet’s lubrication needs will deliver durable anti-shutter performance.

 

 

 

 

 

 

 

Additionally, a synthetic-based fluid offers automatic transmissions other performance benefits, such as the fluid’s resistance to cold weather thickening, resistance to viscosity shearing, extended oil life, and resistance to thermal and oxidation breakdown. Totaling all these benefits together provides a superior fluid that keeps transmission spotlessly clean and performing at peak efficiency.

Another point to consider in determining what is the best automatic transmission fluid would be the durability of such a fluid. Unlike conventional ATF fluids, synthetic based automatic transmission fluids are able to perform in much wider temperature ranges. They can deal with colder and hotter environments. For example, a synthetic ATF fluid offers a very low pour point of -60, making it ideal for extremely cold weather use. At the other spectrum of the thermometer, a synthetic base oil comes with a flash point of 367 degrees F. This ability to withstand high temperatures will come in handy if the vehicle will be working hard in desert temperatures during the summer. In terms of which fluid is the most durable, hands down synthetic-based ATF wins.

Toyota diesel SUV.
An automatic transmission places severe demands on its fluid. It must flow easy and protect critical transmission components in brutally cold weather and must withstand extreme heat so as to maintain its viscosity and protective lubricant film.

 

 

 

 

 

 

 

 

As mentioned earlier, there is no single ATF fluid that would meet all vehicle requirements. Still, the synthetic-based automatic transmission fluid discussed in this blog post can meet a very long list of manufactured transmissions. It can be used in Allison transmissions, can replace Chrysler ATFs before 2006, and can be used in replacement of Dexron fluids. This synthetic ATF fluid can replace the majority of Ford/Mercon fluids, plus other OEMs such as Volkswagen, Toyota, Honda, Mercedes-Benz, Nissan, Mazda, Voith, and ZF transmissions. Please note, when considering the type of synthetic ATF fluid discussed here, it is not to be used as a fluid in continuously variable transmissions (CVTs) or in dual clutch transmissions (DCTs). Considering the versatility of such a unique ATF fluid, ultimately it offers many useful performance benefits. Choosing such a fluid can simplify inventory because of its ability to find use in multiple vehicles. It can be a very productive and cost saving tool for your fleet or operation. Hopefully the information provided here gives you enough data to decide what is the best automatic transmission fluid for your vehicle.

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A useful benefit to choosing a top tier synthetic-based ATF fluid is its ability to meet the requirements for a very wide range of vehicles meaning it saves you money and inventory.