Universal ATF: what does a list of twenty specifications mean?

The easiest answer a salesman can give to “what should I put in my automatic?” is a can labelled “Multi-Vehicle ATF”. The list on its back really is impressive: DEXRON-III, MERCON, Toyota T-IV, Nissan Matic J, Hyundai/Kia SP-IV, Honda DW-1, MB 236.14, ZF TE-ML 14A. The longer the list, the better the fluid, supposedly. But it does not follow at all that it can go into any automatic.

How a fluid for a conventional automatic differs from those for a CVT and a dual-clutch gearbox has already been covered in the article on fluids for automatics, CVTs and DSGs. This one is about something else: what a long list of specifications on one can actually means, and who stands behind each line of it.

In short, a universal (multi-vehicle) ATF is a fluid whose maker itself claims that it suits the automatics of many brands. Claims, note: most of the carmakers whose names are printed on the label have not tested or approved this fluid. Our reference lists about a hundred fluids for automatics, CVTs and wet-clutch gearboxes. Half of them list at least 13 names, thirty more than twenty, and the record holder has 61.

Three parts of one list

The list in the data sheet of such a fluid usually consists of three parts, and the difference between them is the whole point.

1. “Approved”, “licensed”. This is an approval or a licence: the carmaker or the gearbox maker has tested the fluid and entered it in its own list. There can be anything from none to a dozen or more such lines. Multi-vehicle fluids for passenger cars mostly have one or two (say, DEXRON-VI and MERCON LV), while long lists of approvals are found chiefly on fluids for the automatics of trucks and buses (ZF, MAN, Voith) and of older Mercedes-Benz cars. So what matters is not the number of approvals but whether the one your gearbox needs is among them.

2. “Meets”, “exceeds”. “Meets the requirements” or “exceeds”: this is now the fluid maker’s own statement, and nobody else has checked it.

3. “Recommended for use where … is required”, “suitable for”. “Recommended where … is needed” is the longest part of the list, and it is what makes a fluid “universal”. It, too, is backed only by the fluid maker’s word, just phrased even more cautiously.

In one typical data sheet of a universal fluid the approvals line has two names (DEXRON-VI from GM and a Volvo specification), two more come under “meets the requirements”, and the table “recommended for applications where … is required” runs to over a hundred names from some thirty-five brands. And right there it admits, honestly: the manufacturers of the cars and gearboxes have neither evaluated nor approved this fluid for those applications. In other words, that table is not a list of approvals but the fluid maker’s opinion of where it can go.

How to check each such claim is explained in the article on how to check an oil approval; for ATF the rule is the same.

DEXRON, MERCON and ATF+4: names with a licence

American carmakers registered the names of their fluids as trademarks and license them. DEXRON is a GM licence, MERCON a Ford licence. The data sheet of a licensed fluid shows the licence number beside the name: GM’s consists of letters and digits, and Ford’s numbers for MERCON LV begin with MLV. In 2005 Chrysler, too, began licensing its ATF+4.

But look at which of these names turn up most often on “universal” cans:

So “DEXRON-III” or plain “MERCON” on a new can is always just a claim, even if the data sheet still lists it among the approvals: there have been no valid licences for these names since 2007. In our reference DEXRON-II or DEXRON-III is named for 47 fluids and plain MERCON for 32, while only a few fluids hold a licence or approval for any DEXRON or MERCON at all.

It is the gearbox maker, not the seller, that replaces an older fluid with a newer one. It was Ford that decided that gearboxes specified for MERCON are now serviced with MERCON V. MERCON LV, though, in Ford’s own words, must not go where MERCON V or ULV is required, and MERCON ULV must not go where V or LV is required. A fluid with two licences, DEXRON-VI and MERCON LV, does exist, and it suits a gearbox that calls for either of them. But two licences are two licences, not twenty.

Japanese, Korean and European names

Toyota T-IV and WS, Honda ATF Z-1 and DW-1, Nissan Matic D, J, K and S, Hyundai/Kia SP-III and SP-IV, Mitsubishi SP-III are neither quality classes nor standards, but names of a carmaker’s own branded fluids. The Aisin Warner specifications JWS 3309 and 3324 are usually printed on data sheets alongside T-IV and WS: they are the numbers of the company that supplies the gearboxes themselves. In our reference Japanese and Korean names appear on fifty-odd fluids, and on only one of them is such a name entered as an approval. The rest say “meets” or “recommended”.

And what do the carmakers themselves say? In its service bulletin on WS fluid Toyota states plainly that it is incompatible with both T-IV and DEXRON, and that additives or third-party fluids regarded as “compatible” or as substitutes can cause shifting problems and damage the gearbox. In other words, two names separated by nothing more than a comma on a “universal” can are, for Toyota itself, incompatible fluids.

With European names it is the other way round: here there is something to check. Mercedes-Benz has a public list of approved operating fluids with separate 236.x sheets for automatics (sheet 236.17, for instance, is for nine-speed ones), and every sheet names specific fluids. If a fluid is not on the sheet, “MB 236.14” on its can is only a claim. ZF keeps its own TE-ML lists; what their numbers and letters mean is explained in the article on ZF TE-ML approvals. And codes such as VW G 052 162 or G 055 025 are part numbers of original Volkswagen fluids, not standards at all.

ZF makes this especially plain. On the fluid for its eight-speed 8HP automatics ZF is unequivocal: only ZF LifeguardFluid 8 or 9 (or the same fluid in the carmaker’s packaging) may go into these gearboxes, because other oils can lead to anything from noticeably worse shifting to a failed gearbox. Meanwhile some universal fluids list LifeguardFluid 8 among the applications they are “suitable for”. Whom to believe — the gearbox maker or the fluid maker — is, I think, a rhetorical question.

Why one fluid cannot suit everything

The point is that the fluid in an automatic does not merely lubricate. The clutches (the disc packs) and the torque converter lock-up clutch rely precisely on friction in the fluid, and the gearbox maker tunes the gearbox to the particular friction characteristic of its own fluid: how quickly the discs “grab”, how the fluid behaves while slipping. ZF, for example, says outright that shift quality depends on the fluid’s friction being matched to the gearbox. Add different viscosities (newer fluids tend to be thinner than old ones) and different seal materials.

A universal fluid is a compromise here: its friction is acceptable for many gearboxes, not spot on for yours. It is rather like “one size fits all” shoes: you can put them on, but how far you will get in them is another matter.

It is telling that the data sheets of universal fluids themselves say where they must not go. One states outright: not for CVTs, not for dual-clutch gearboxes and not for newer Mercedes-Benz automatics (sheets 236.12, 236.14, 236.15 and 236.16). So “for everything” in fact means “for many, but not for all”.

When a universal ATF makes sense and when it does not

A universal fluid makes sense in two cases.

1. The can carries exactly the approval or licence entered in your service book. Say your gearbox asks for DEXRON-VI, and the data sheet shows DEXRON-VI on the licence line, with a number. Twenty more names beside it change nothing: for your gearbox it is simply DEXRON-VI.

2. The carmaker itself has allowed the substitution. Ford services old MERCON gearboxes with MERCON V, and GM mostly allows DEXRON-VI for its older automatics. In that case look on the can for a licence or approval for that newer fluid in particular, and if there is none, buy the carmaker’s original fluid.

Only the carmaker’s fluid (or a fluid with its approval) will do in these cases.

1. A car under warranty. Use only the fluid from the service book, or after a failure you will most likely lose the argument with the dealer.

2. Modern eight-, nine- and ten-speed automatics. For the ZF 8HP only LifeguardFluid 8 or 9, for nine-speed Mercedes-Benz a fluid from sheet 236.17, for ten-speed Ford and GM the ULV fluids.

3. A CVT and a wet dual-clutch gearbox. Their fluids are not interchangeable even with each other, and the data sheets of universal ATFs quite often exclude them outright.

4. An automatic for which the book specifies a branded Japanese or Korean fluid. Behind “T-IV”, “Matic J” or “SP-IV” on a universal can there is usually nobody but the fluid maker, and Toyota has already had its say about “compatible” fluids.

I will say it again: a long list on a can of universal ATF is not twenty approvals but a few approvals (or none at all) and, for the rest, promises. Look in it for the name from your service book and see which part of the list it appears in. The original fluid costs more than the universal one, repairing an automatic costs incomparably more than both, so where to economise is up to you.

Further reading:

• What are “original” operating fluids?
• Is it worth using analogues and substitutes?
• How to extend the life of an automatic gearbox?