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Transmission Fluid Guide?

When one takes into account the multiple types of transmission fluid across makes of cars (e.g. Toyota vs. GM vs. Chrysler etc.) and then multiplies that by generational changes and variations within type (e.g. Mercon through Mercon V and now Mercon SP) verifying the correct and optimum transmission fluid seems to become a nightmare for anyone who isn’t constantly following the industry.

Owner’s manuals don’t work - since they are frozen in time while the fluids change over time. Auto parts store employees are generally useless for this. Dealerships are not only more expensive but are also often much less convenient to get to and not as easy to deal with as a basic auto parts retailer.

Does anyone know of any (preferably online) definitive source for verification of proper transmission fluid type? I haven’t been able to find one. Preference would be for something not tied to any specific manufacturer or marketer of lubricants - since their job is to sell stuff, not make sure that you get the right stuff.


[If anyone must know what finally prompted me to post the general question]:

- I went to a Fisher AP to buy a quart of Mercon V for my '97 Ford Escort. They didn’t have any. The guy at the store told me he “thinks” that some Dex IV stuff they had supersedes Merc V. I wasn’t going for it. The Dex IV bottle specified that it also met specs of Mercon SP, but as far as I know SP is fairly specific to only certain Fords, and doesn’t replace Merc V.

- Anyway, I don’t care about all of that. I’m going to find some Merc V b/c I know it is fine. I just need a good way to sort out the mess anytime I have a trans fluid question for any reason.

Your owner’s manual isn’t as useless as you think. It should clearly say in the specifications section in the appendix. For instance, my Accord owner’s manual says Honda Z-1 fluid only, or an Acme fluid only if its an emergency.

The common fallacy of the owner’s manual is that it may give you unrealistic change intervals. For instance, my Accord owner’s manual also says to first change it at 90k under normal conditions. Yeah right. I did buy the car used at 118k or so and I have since changed the fluid and plan to again in another 7k or so (car now pushing 140k).

In short, change the fluid every 20-30k miles.

Jeff - I can’t even buy the fluid specified in the owner’s manuals of my three vehicles. My '95 Caravan wants ATF2 ; my Olds wants Dex III; my Escort wants Merc - not Merc V. The problem is that the fluids get updated. Then you’re often supposed to use the new version. Then no one makes the old version anymore, and often the manufacturer will tell you the new one is better.

For definitively answering questions about type of fluid the owner’s manual is useless.

Have you checked the oil cos.’ web sites? Some (Castrol, Valvoline) offer guidance.

I am amazed, though, that I haven’t found a simple chart saying something like ‘if your car calls for X (original fluid), you now should use y (modern equivalent)’.

Amsoil has a synthetic universal transmission fluid that can be used for most automatic transmissions out there except Ford CVT or type F. I have never used it but this has been around since 1980 and they are still in business. Here is the link:

When in doubt you could contact the parts counter at the local dealership or a transmission shop for the information…

Hey Cig, sorry, didn’t realize you were the O.P. until now. I guess I misunderstood your question, but it looks like Tex and Missile have you steered in the right direction. Regards.

The general suggestions are good as always - thank you. I do avoid any of those kinds of fluids that claim to be “universal” (e.g. Amsoil) or even cover multiple types (which a lot of the major oil cos try to do). The basic problem there is that their interests and mine conflict. They want economy of scale. I want the exact best thing designed to specs for the transmission under question.

And as opposed to calling the right kind of dealer for any question I might have, what I had in mind was something in the family of a “Gates guide” for up to date transmission fluid info. You know - if you want the skinny on the timing belt specs for any year/make/model you go to the Gates guide. I want one for trans fluid - so if friend X needs to know what to do about trans fluid I can find out, or if the guy at the parts store tells me I can use Dex IV instead of Merc V I have some source to turn to.

Valvoline has a fairly comprehensive guide - but they do that thing where they recommend the same “Maxlife” fluid for tons of different cars. I found a comprehensive official Motorcraft one for Ford that goes by transmission model - which is useful if I only want to know about Ford (I did at least verify that Merc V is the official word for my Escort - SP is totally out and there are no other kinds of substitutes).

But where is the “Gates guide” for trans fluid? I can’t find it. I’ll probably now forget about it until the next question comes up for some reason…(This wasn’t the first time I’ve wanted to find it).

You’re really down to two fluids now. ATF + 2 and DexronIII/Mercon. I have been using various brands of Dex III/Mercon universal fluids for a long time (as has my trusted mechanic) with good (no negative) results. You could upgrade to Dex VI for the Dex III/Mercon applications without any issues. I have not done so, but don’t see the economic or performance advantage in doing so. Dex III/Mercon is widely available at all the chain stores and Walmart.

ALL automatic transmission fluids are basically the same. They are all low viscosity hydraulic fluids that have been fortified with anti-foam and anti wear and detergent additives. Car makers, when they discover a design problem, instead of correcting it, formulate a “special” fluid to deal with the design problem…Next thing you know, we have 20 different kinds of fluid…But it’s all basically the same…The old “Type F” is indeed a different animal…

Chryslers official position is that ATF+4 is the replacement for all cars calling for ATF+2 and ATF+3.

See if this link is any help.

The general suggestions are good as always - thank you. I do avoid any of those kinds of fluids that claim to be “universal” (e.g. Amsoil) or even cover multiple types (which a lot of the major oil cos try to do). The basic problem there is that their interests and mine conflict. They want economy of scale. I want the exact best thing designed to specs for the transmission under question.

The fear factor is unwarranted. Do you think that XOM and Mobil 1 specifically are into serious risk management with their fluids? Not at all. They (one of the majors) blended the OEM fluid to begin with. They’re well schooled on what is required for your trans and have well funded R&D staff and facilities to assure it.

Continual evolutions in fluids are a revenue stream for the OEM. Did we really NEED Dex VI to be created? Was there really anything wrong with the previous evolutions? Nope, but now someone is paying a pretty high ante to have a licensed product.

Something more to consider. Go and ask several trans shops what they use when servicing their customer’s trannies. Except for the real oddballs (which yours is not) they use a universal fluid. They may carry 2 bulk fluids when the Dex VI applications start showing up in higher frequency. For now they may just use bottles. The stuff is thinner than most fluids.

There was a study published for SAE. It was a GM funded study conducted by two GM power train fluid engineers that showed that Dex VI showed superior performance over multivehicle formulas. So, talk about conflicts of interest. A GM funded study, by GM personnel, proved that GM licensed fluid worked better than the competition. If the study didn’t show that, it never would have seen the light of day. The study was assured to be configured in a manner that would assure that result.

Cigroller, I Hear You ! Also, I don’t think you’re being overly cautious.

A lady I know let a trans shop substitute Mercron (universal fluid ) or whatever in her Chrysler product that called for ATF + X (X = number) and it immediately started slurring shifts.

Since you’re not changing / adding all cars at once, you could start with the Ford. I’d waste the time and trip to the nearest Ford dealer and see what they sell for the 97 Escort that uses Merc V. It seems as though the parts department should have quart bottles and I’d read what the bottle says. You don’t have to buy from them if it’s too expensive.

Then I’d do this for the other cars when it’s convenient.

Maybe Ken Green will weigh in for some help.


I’m Still Looking For A List. Here’s What I’ve Got So Far. (I Don’t Know That Anybody Can Keep Up With It And Make A Definitive List.)

Did you see this one ?
Notice what is says for Chrysler ATF+3 and Mercon substituting.


CSA - that one is a beauty and I’m not sure how I didn’t find it. I’ll bookmark it though and hope that it gets updated over time.

And thanks for agreeing about playing it loose with different types. I have talked to & heard from too many tranny experts to use only the specific fluid and that all fluids are certainly NOT the same. I have also been warned by knowledgeable people about the multiple spec fluids. (With some possible exceptions such as Dex III/Merc).

I figure why not use the manufacturer’s recommendation? What do I gain by buying something that some company or mechanic “claims” is just as good. It may be little to no risk. But I can’t find the benefit.

I agree. It’s always wise to do as you’re told and not educate yourself in the topic at hand. Why bother, it’s only knowledge?

That’s a fairly bizarre thing to say since this whole thread was about me educating myself. I think that what you meant to say is that you must be insulted because I won’t just accept what you told me.

A glance around the transmission fluid world is plenty to tell one it is complex. If you wish to keep it simple that is fine. Why is does it seem so strange for me to want a simple guide to up-to-date transmission fluid recommendations? Its really not such a weird and outlandish thing. I’m somewhat stunned at the assertion that this is somehow a silly, frivolous, and misguided thing. If you think so that is fine. I don’t think so - and I’m not just making up my concerns. I promise you that I didn’t just stumble across transmission fluid issues recently. There are plenty of other threads where you can probably help people instead of making snide and useless remarks. So why not ignore this one and go help someone where you can?

Well, you’re way too easily convinced that XOM, Castrol, Pennzoil, and every other major blender/refiner would put themselves at risk for class action law suits for damaging millions of units with the stuff that they sell over the counter by the fuel tanker load.

If you can entertain that totally ridiculous notion, then you’re more easily swayed by what one data point tells you …and dissuaded from a preponderance of evidence to the contrary.

How long did Honda keep the ball in their court with alleged proprietary fluids? Coolant, ATF, you name it and the part counter loved your money. Same with Toyota and everyone else. Get used to more of it. As the pickin’s get slim …they’ll gouge you more through another door. Look to more synthetics with oddball spec’s that require a blender to pay a higher ante to be allowed to put the official license badge on the bottle.

This is not to say that you’re doing yourself a disservice if you’re truly informed and fully aware. I think that you are not and that you’re reacting out of some fear factor.

Otherwise, I have no problem with your disposition …and have a nice day.

Fact: manufacturers maintain transmission fluid recommendations

Question: does anyone know of an up to date list?

Its a pretty damn simple question so I’m not sure exactly why it bothers you so much.

I’m sorry if what you really wanted me to ask is “is there really any difference between all of those fluids?”