Suitable substitutes for the Toyota ATF-WS transmission or transaxle fluid?

I was ordering parts on Rock Auto for my '13 Prius V. I was surprised that they had what appear to be two fluid choices that are exclusively WS spec. Meaning not just an approved replacement for 8 types of transmission fluid, including WS... but exclusively labeled as WS auto trans fluid. As I was placing an order already, I added 4 quarts to my order. (it was half the price the dealer charges)

The brand I went with is made by Aisin (Toyota's transmission supplier).

The other is made by Beck/Arnley (an aftermarket parts supplier that I have mixed feelings about)

Rock Auto also had a third option listed, but looking at the label, I didn't see any mention of WS spec.

So I received the Aisin fluid. I was curious if it was simply the same as OEM Toyota fluid -- just in a different bottle. It appears not to be, as the color was a brighter red with the Toyota fluid. ( I had a partial quart of Toyota fluid from the last change, so I put a couple drops of each on a white paper towel to have a look.) Sorry, didn't take a pic.

I'll keep it in there for this interval, but I think next time I'll go back to the Toyota fluid. I'm sure this Aisin fluid is just fine though.

 

Neither is full 100% synthetic.

 

There's no indication on the bottle that the Toyota fluid is either.

 

That's what I meant.......neither.

 

WS is a good, low viscosity ATF similar to Dexron VI. Most high quality ATFs that fulfill the Dexron VI standards probably also fulfill the WS standards. It is not unusual for the technical data of two differently labelled motor or transmission oils from the same manufacturer to be absolutely identical.

Multiple labelling of the same product is often helpful for the consumer to avoid confusion and to choose the correct product. But sometimes it is used as a marketing trick, to trick consumers into buying two packages, instead of one, of the same product, in the belief that they are buying two different, specialized products.

 

Been using Red Line D6 for the past 10,000 miles. No change in mileage, sound or anything else. Changed at 70,000 miles, the stock fluid looked pretty nasty.

I'll change it again at 100,000 miles and see how it looks with an analysis. Until then I'm happy with it.

 

Dexron fluid likely does not have electrical insulation specs because it is not usually used to cool electric motors.

 

Doesn't matter there is no fluid interaction with the windings. Fluid is only used in the differential/sun gear section of the trans.The trans is cooled by the inverter fluid which is circulated through chambers surrounding both mgs.
There is an excellent tutorial on YouTube the Weber technical school where they disect both g2 and G3
Transaxles.

 

Hi Ed, I basically agree with you, that the Prius transaxle does not necessarily need an ATF that is specially formulated for the stator windings. But I come to that same conclusion with different reasoning.

I have been watching some of the the Prius transaxle disassembly videos at WeberAuto on YouTube, and it looks to me and also to Mr. Kelly that the ATF comes in contact with the stators and their windings. In fact, Mr. Kelly specifically states this in the comments section of one of the videos when asked by a viewer. (3rd Generation Prius Transaxle - P410 Quick Look)

But any ATF that meets the usual standards does not contain solvents that would harm the relatively delicate plastic and rubber parts of conventional automatic transmissions and their hydraulics, much less the relatively robust insulation of the stator windings.

And the dielectric strength of ATF is typically around 35 kV. Dielectric oil for high voltage transformers generally needs to have a dielectric strength of at least 30 kV. I am no expert, but I think that is far more than enough for the HSD, which would probably still be fine with just 1 kV.

 

...when they do NOT say to use only their brand of engine oil or filters or brake fluid or coolant? There is a reason.

 

With the coolant, while they don't say it's mandatory to use their coolant, they do put a number of cautions in there, about the formulation of alternate fluids. I read all of that, have no idea what they're talking about, stick with Toyota fluid, for 100% compatibility. And hey: it's pink.

 

The Ashland or Valvoline Asian coolant meets those specs. Possibly others as well.

 

I used a non-oem oil. In Europe there is a popular french oil manufacturer with high quality products - Yacco. Their products aren't cheap, but compared to the local Toyota prices, the cost is in half.
Around here, Toyota ATF-WS costs $94 and the Yacco (ATF XFE) is $48. Its spec sheet says it has the properties of the Toyota WS type oil: Yacco ATF X FE.

Changed mine at 100k miles and the one that came out was VERY VERY dark, almost black. Definitely should be changed.

 

That's $94 US dollars for Toyota ATF-WS? Per quart or litre? Either way: that's terrible!

I pay $9.14 Canadian (about $7.22 US currently) per litre.

 

Perhaps import duty to Belgium?

 

maybe, but what does it matter if he lives in bulgaria?

Sofia, BG

 

I have been changing mine every 50,000 for millers fully synthetic on my old gen2 my son-in-law has now. It has over 200,000 miles now and it did seem smoother when I first changed it. I will do the same in my pip once warranty is out

 

Also interesting is the comparison to air, since the transaxle is filled mostly with air:

(from Electrical breakdown - Wikipedia )

Obviously, since all non-insulated electrical parts above the oil level of the sump are separated primarily by air (and even below the normal oil level for a short time when the oil sloshes around), the transaxle must be designed to function properly when the gas or fluid inside has as little as 3 kV/mm dielectric strength.

 

Sorry, that's for the total quantity needed, 4 x 1L bottles, so 23.5 USD per liter.

I'm from Bulgaria The prices here are waaayyyy different from the ones in the US. For example, the labor is relatively cheap, but the parts/goods are expensive due to the import taxes (if the goods are from outside the European Union) + 20% VAT + the huge surplus charges due to the lack of competition or agreements between the "competition". New cars are also vastly more expensive, the gas prices are high (as in whole Europe), for example a gallon of regular gas is 4.61 USD/gallon and this is cheap compared to two years ago when it was up to 6.60 USD/gallon.

 

A summary of alternative ATFs being used by people in this thread, so far: