Automatic Transmission Fluid choices: detailed information
by David Newton; 4-1-09
Premise:
So many times we ask ourselves what is the right choice for fluids. And when it comes to transmissions, there is just as much mythology, misunderstanding, and misconception as with any other lubricant. I’d like to try and lay out the choices for you, and do it with logic and factual basis. I’ll leave the brand wars and opinions to others.
Background:
The automotive industry is fairly diverse, and only occasionally do products come together in symbiotic relationships. For some time, that was true of the GM Dexron III and Ford Mercon fluids. These fluids were so similar that the aftermarket lubricant companies could produce fluids meeting both specs, thereby saving development and marketing costs by sharing products across two large OEM product lines. However, nothing lasts forever. GM and Ford have gone their separate ways regarding transmission fluids, and the ATF lineage has larger disparity in it now.
Conceptual Thesis:
I’ll discuss many options, but what you have to understand is that there are going to be references to basic fluids (“dino”), synthetic fluids, Allison specs, GM specs, and “cloned” as well as “licensed” products. I’ll discuss “performance based” and “chemistry based” fluid differences. All these have their niches for appropriate markets. I’ll stick with the concept of GM fluid specs for this discussion, specifically relating to our Allison 1000 series transmissions, and our NV 261/263 t-cases to a lesser degree. Note that this does not address other types/brands of vehicles and/or fluids. For example, I am not referring to Chrysler ATF+ ... fluids, nor Honda specs, etc.
Nomenclature:
It’s very important to note that the letters “ATF” have very different meanings in the same sentence. “ATF” can mean “automatic transmission fluid”, or it can be a specific brand reference to a specific product (such as “Mobil 1 Synthetic ATF”) which denotes a singular product in the brand line. The same can be said for the use of the terms “DexronIII/Mercon”, “Dex/Merc”, “D3/M”, and so on. The full use of the words “Dexron” and “Mercon” are controlled and licensed by GM and Ford, and no longer are available for use in reference to past fluid revisions. But the implication is still there by the use of the abbreviated terms. However, it’s also important to note that abbreviated terms also may come with abbreviated performance. Read on …
Options:
There are several fluids to choose from. The base fluid we’ll discuss is Dexron III(h), commonly referred to as “DEX III”. It is of conventional base stocks and additives. It is no longer licensed by GM, as Dexron VI (DEX VI) has usurped it. DEX III was a performance-based fluid specification. In other words, if you wanted to market a fluid for DEX III, as long as it performed to a certain level with specific criteria, you could be “approved” by GM to be DEX III licensed, pending passing the application and testing phases. However, as always, there are “upgrades” that can apply to DEX III fluids. You can have “synthetic” fluids that meet/exceed the base criteria, and outperform the minimum approval levels. These type fluids are “better” than the basic fluids. Under the former system, they would have still needed to be licensed to be “approved”, but the market was large enough to warrant such cost expenditures. In contrast, DEX VI is now a chemistry-based fluid license, rather than a performance-based license. To qualify for licensing by GM under DEX VI, you must use a proprietary chemical additive package. No longer can you just perform the same as DEX VI; rather, you must now be chemically identical to, DEX VI. This represents a huge shift in the fundamental understanding of how the transmission fluids are made. You can no longer “walk like a duck and talk like a duck”; you must be a duck at the genetic level.
Next, let’s consider the TES licensed fluids by Allison. These would be known as TES-295 and TES-389 fluids, among others. The TES-295 fluids are what Allison considers to be the “best” of all fluids. They are highly refined, have premium additive packages, and are tested thoroughly to the utmost standards, based upon a performance standard that is very high. The TES-389 fluids are what would have previously qualified as DEX III fluids, also based upon performance. It is important to note that TES-389 fluids do not include DEX VI; the chemistry and fluid characteristics are greatly different. They are compatible to be mixed, but they are not at all the same. The additive packages and base stocks are very different, and therefore the resultant fluid properties are also different.
Nearly all the fluids are DEX III designed in basic structure. The TES-389 and TES-295 and “synthetic” (former) DEX III fluids are all similar in that they can pass the minimum criteria that would have been DEX III. What we have to understand is that any licensing procedure can be expensive to go though, and many companies no longer choose to participate if the market sales does not override the costs. Regarding the former DEX III, only Allison has a compatible license (TES-389) that is essentially a continuation of DEX III. I cannot fairly claim it to be exactly the same, because it’s not legally. But conceptually, it is similar. But fair warning exists in that products can have similar/same marketing names, but not the same performance guarantee! For example, some of the TES-389 licensed fluids have names like “DIII”, “D3” or “D/M” depending upon brand. But there are other companies that also use these designations, which are not licensed by Allison under the TES-389 program. You will often see house brands by Autozone, Advanced Auto Parts, etc. that have Dexron III / Mercon “equivalents”, but they cannot claim the performance guarantee. In fact, they cannot even use the “Dexron III” and “Mercon” names in the labeling or packaging referring to the older specs, because there are no valid licenses any longer. They often refer to these fluids as “vehicles that would have previously used …” and such. The main reason is that no one can claim a guarantee to a system that is no longer “licensed”. So, there is no governing body that oversees the fluids for a qualification system that no longer exists. (Technically, GM and Ford still own the rights to those names and specs; they just don’t license them any longer for use). Think of “Dexron” and “Mercon” as the brand name of a product line, and the “III” or “V” or “VI” or “LV” as the specific product, and you’ll better understand.
The exception is DEX VI for GM (and Mercon V and LV for Ford). The DEX VI uses a slightly different base stock, with a vastly different additive package. This fluid is far superior to basic former DEX III fluids, and even TES-389 fluids, because it has approximately twice the viscosity retention, and oxidation resistance, as the former fluid it replaces. It is “thinner” in nature, but it stays in grade much better and longer than traditional DEX III fluids. The main concern surrounding the use with DEX VI in Allison applications is that DEX VI has compatibility issues with some of the seal materials formerly used by Allison. Allison has established serial number cut off’s for use of DEX VI (S/N 6310670488 and up for Indianapolis built transmissions, AND... S/N 6320784373 and up for Baltimore built transmissions used in GM pickups.)
The Name Game:
“Synthetic” ATF fluids are available in many forms. But for our discussion, we’ll limit them to (former) DEX III based fluids. Here’s where it really gets tricky for some to understand. It’s almost easier to talk about specific fluids, so that examples are clear, rather than to talk of generalities. Exxon/Mobil has a product called “Mobil 1 Synthetic ATF”; it is a PAO synthetic based fluid and has excellent properties, and is useful in a wide range of applications. Amsoil has a similar product, called “Amsoil ATF”. But because Amsoil does not have a specific DEX VI product, they use “ATF” to encompass the DEX VI application. Mobil, and many others, actually have licensed DEX VI fluids; they pay for the chemistry package and subsequent licensing. Further, Amsoil would suggest use of their “ATF” for both DEX III and DEX VI applications, and “TorqueDrive” for the TES-295 fluids. Yet Mobil would suggest “D/M” for former DEX III and TES-389. Oddly, the Mobil 1 “Synthetic ATF” is NOT approved for TES-389 (as of this writing), but it is an upgraded DEX III fluid, far superior to their “D/M”. Mobil actually chose to not apply for the TES-389 license, even though the “Mobil 1 ATF” would have easily surpassed the tests. Apparently the marketing return was not worth the investment. Sounds a little like Amsoil, doesn’t it. See how licensing and non-licensing can convolute things? Mobil would rightfully suggest their use of Delvac Synthetic ATF for TES-295, as it is licensed. What you get is this huge overlapping blanket of brands, names, and licenses (or non-licenses). It’s no wonder that people get confused. And now, there are “semi-synthetic” and “synthetic-blends” in the market. Of note, Mobil has a “Multi-Vehicle ATF” that is “suitable for use in” many applications, and “approved” for a smaller list of others.
Since Amsoil doesn’t apply for licensing in most avenues, they cannot claim to be DEX VI licensed. This very much is similar to the whole “what the meaning of “is” is” argument from a former president. When you read the words “approved” and “suggested” and “recommended” and “suitable for use in”, you must ask yourself how these words are used against a standard reference. Amsoil will recommend their fluids for certain applications, but that doesn’t mean that the fluids are “licensed” by the OEM. In no way does that discount the abilities of some non-licensed fluids; it just speaks to the methodology/marketing of the brand. What you get when buying a non-licensed product is a lack of OEM guarantee. However, many companies also have their own guarantee, supplementing the OEM products. Your risk level varies with the degree of licensing, and your exposure reflects inversely with the coverage of licensing. Just because something is not licensed, does not make it inferior. However, it cannot be judged as “approved via license” because the application was never made. Two shining examples are Amsoil’s “ATF” and “Mobil 1 Synthetic ATF”. Both are premium fluids, with limited or/no approvals for all applications. In fact, Amsoil ATF is not “OEM approved” for any application that I know of, and the Mobil 1 ATF is ONLY “Allison C-4” approved. And yet they serve admirably in many, many different applications; they are fantastic products. It all comes down to the ROI considering the licensing and the expected target market(s).
That brings us to the “clones”. This is a term which often is applied to TES-295 non-applicants. The clone fluids are designed, both in base stock and additives, to give performance equal to licensed fluids. The issue of viability comes from who judges the applicants. Since the clones are not submitted to Allison for verification, there is no license issued. But if you accept that other entities can break down, analyze, and mimic the licensed fluids, then it’s reasonable to believe that performance will be similar/same to the licensed fluids. In oil analysis, it is difficult (if not impossible) to tell the two products apart. Amsoil, Schaeffers, and DA Lubricants all have clones available. The upside to these fluids is that you get the performance of TES-295 fluids, with less development and management costs. The disadvantage is that there are no license rights.
The crème-de-le-crème is the TES-295 licensed products. There is no higher claim-to-fame than these. These are based upon the former Dexron III / Mercon fluid structure, but far surpass the capabilities of those conventional fluids by use of premium base oil stocks, and outstanding additive packages. They are tested in very rigorous conditions, and are very robust. They are only licensed by Allison.
Warranty:
The OEM that sold you the vehicle is the one that warrants the product. Even though Allison made the transmission (past tense), or NV the t-case, only GM warrants the products as sold in the light-duty truck line. If warranty is your concern, then use fluids directly specified by the OEM. Unfortunately, GM is known for some rather ambiguous and misleading manuals. Some years of trucks don’t mention TES-295 licensed fluids as options, while others do. Allison would suggest TES-295 as the top choice, but they are no longer a part of GM. GM kept the 1000 series transmission in the sell off for the light duty trucks, and probably the naming rights for that specific application. But GM wants you to buy DEX VI because they license it, and therefore they make money from it. If you’re out of warranty, then you have a much broader spectrum to choose from. And let’s not forget that the fluid manufacturers also have written warranties. As long as you stay within the confines of their recommendations, you would be covered as well.
Synopsis:
If we could break this down into simpler concepts, I’d have to say this:
Unlicensed fluids are an unknown. They are not all bad, nor all good. They are simply uncontrolled, and you must rely on your trust of the lubricant manufacturer’s ethics and warranty to develop your own comfort level. From a perceived “least” to “best”, I’d rank the fluids in the following order:
1 Non-licensed former DEX III basic fluid types, and non-TES-389 licensed
2 Licensed TES-389 fluids
3 DEX VI fluids
4 Synthetic (former) DEX III type fluids
5 Synthetic TES-295 fluid clones
6 Synthetic TES-295 licensed fluids
Be aware that 3 & 4 are very closely related in performance, with the slight edge going to the Synthetics former DEX III types. But also know that there are now “synthetic” DEX VI products, which are now even breaking through this barrier (of note, Valvoline has a “full synthetic” DEX VI now). Also be aware that the performance difference between 5 & 6 is not nearly as wide as the cost difference between the two. Often, they cannot be distinguished in oil analysis or performance, but only by your wallet. A note of caution: do not discount a fluid simply because it is not licensed. You must research the particulars of any one fluid to make fair determinations.
Conclusion:
I hope this helps understand the choices, and their pros/cons. I didn’t choose to name specific fluid brands and products due to my preferences, but rather to illustrate the similarities and differences between the concepts discussed. Only you can choose which fluid is “best” for your application. It is merely my intent to offer the information in an easily consumable format, for you to make good choices
