Transmission fluid

Toyota power-split hybrids(only type in the Prius) do not have an automatic, whether step or CVT, transmission. It gets labelled as an eCVT because it behaves like a CVT, but mechanically is more like a manual/standard transmission. Manuals do not need a fluid that also works as a hydraulic fluid; they just need lubrication and perhaps cooling from the fluid.

I believe Toyota chose ATF WS out of convenience. The available fluids for manuals were too thick, impacting efficiency, and they didn't want to invest in a dedicated fluid for one car model. With all the hybrid models, and BEVs, they finally made that investment.

 

I was thinking the same thing. Presently I have four quarts of Idemitsu Type H2 queued up for my son's 2016 Accord. We'll see how that goes before making any decisions on the Prius V.

 

I wonder if TE would actually work in earlier gen transaxles and give a small mpg boost? But I wouldn't want to be the one to test it. lol

 

My guess the main difference is in heat tolerance; ATFs aren't. The gen4 got a more substantial fluid cooler. By substantial, it now runs fluid through the car's radiator like all automatic transmissions do. Before that, there was a spot where the fluid could shed some heat to the inverter coolant loop.

Does the gen5 still have that extra cooling the gen4 got?

 

No, Toyota Genuine ATF WS is for Gen 4 and older Priuses.

 

Here is the viscosity and other data for WS, FE, and TE. TE’s viscosity is by far lower than the other two’s.

ATF WS or CVT fluid | Toyota Nation Forum

With any lubricant, certifications are critical. Do not use a lubricant that does not have the required certifications, as some specs and performance benchmarks might be off.

Typically, a higher viscosity results in less wear and a lower viscosity results in higher fuel efficiency. So, do not use a different viscosity than recommended, as it could adversely impact the wear and/or fuel economy.

 

Don't have a warm viscosity for it though.

 

Which is what he said. The post he was replying to was asking about what to use in a 2017 Prius v.

 

The TE KV100 is a lot lower than that of the WS and FE—no doubt—probably around 4.5 cSt. The pour point is also a lot lower—indicating a thinner and/or higher-quality base oil.

Infineum Insight | Low-viscosity transmission fluids

 

Yes - my bad for discussing two vehicles with different fluid requirements in the same thread. My thoughts on these vehicles now stand as follows:

2017 Prius V with 51k miles: It calls for Toyota WS. I am leaning towards the Idemitsu TLS-LV as it is readily available and probably the same as the Toyota branded fluid. I plan to change it at 60k which could be close to two years down the road the way this vehicle is used.

2023 Prius LE with 49k miles: It calls for Toyota e-Transaxle Fluid TE and will get that next fall when it hits 60k. This fluid is readily available from a nearby Toyota dealer.

If anyone feels that these are bad choices please feel free to comment.

 

If you read the Infineum article I linked above, you can realize how-complicated lubricants modern transmission fluids are.

So, don't mess with it, and buy your transmission fluid from the Toyota dealer.

 

Meh. It looks like Idemitsu TLS-LV is what's in the Toyota WS bottles. That's one I'd feel safe using. But I can't find it cheaper than I can get WS online at my usual Toyota parts stores. So my preference order would be WS at online Toyota stores, then Idemitsu from online retailers, and then finally WS from local Toyota dealerships.

Idemitsu is probably making TE for Toyota, but it doesn't look like they're selling it themselves yet.

 

Obviously, Toyota themselves do not make any lubricants. For example, TGMO in the US is made by ExxonMobil.

E-transaxle fluid TE is made by Eneos, not Idemitsu. Yes, it is the same thing, but unless you live in Japan, it will cost you more than the Toyota OEM label.

Answering @Trollbait's question, KV100 is only 3.3 cSt. It uses a very thin Group III base oil (severely hydroprocessed petroleum base stocks, not the fancy Group IV or Group V laboratory-made base stocks) with new antiwear/extreme-pressure/friction-modifier additives, which I am guessing are partially organic.

ENEOS EV/hybrid e-axle fluid TE