Hello everyone. I have to say that this Prius is a great car, cheap to fix, and has a bulletproof transmission. I tried near 4 new quarts of Toyota WS at 100k, lasted nearly 10k without getting dark.(still had a mild wine) Tried 4 quarts of D6 at 110k and the trans became very quiet. The fluid actually conducted a little bit of electrical current enough to feel a slight jerk in the drivetrain by engine revolution. (Not a good feeling so it came out) Tried 1 quart of Toyota ws with 3 quarts of D6 and it felt smooth without any electrical disruption. Lasted 12k miles without getting dark. Tried near 4 quarts of Aisin WS and the transmission whine and electrical disruption was silenced and has been running perfect for 70k miles (still bright red) Prius V at 180K running very smooth. Toyota WS (40*C= 23.3 cst /100*C =5.3 cst) Redline D6 (40*C= 28.4 cst /100*C =6.0 cst) Aisin WS (40*C= 34.7 cst /100*C =7.3 cst) Cst= centistoke measurement (the greater the number the slower the motion [but better protection in my opinion]) Clearly Aisin developed their own fluid for this very reason. Toyota is skimping by manufacturing WS elsewhere. Aisin is the clear winner.
Here's the red cape @Mendel Leisk . WS is what came in the transmission, so I replace with what came with it. For how little you have to do this activity, why not replace with what's there to start with .
How many miles per month are you racking up on this gen3 v ? Have you had a chance to read this @Tim Jones v thread: I will go down in Prius Trani History | PriusChat Would be interesting to know why the fluid darkens so much faster on the v. Could you please describe what your perceived transmission whine and electrical disruption sounds like, and at what speeds. I've noticed a particular gen3 which has a type of whining noise at slower speeds (under 15 mph), it sounds somewhat like a distant emergency alert PA horn. One other gen3 owner rode in this vehicle and thought it sounded fine/normal, but I'm still not fully convinced. Maybe if I took a ride in a different gen3 it would offer me a better perspective on what normal might be.
This Prius has been used as a cross country travel car probably racking 100k per year. The whine came as soon as Toyota ws started to be used as the majority of the fill. The whine goes away completely because aisins ws custom formula, which has acrylamide and a few other formulations that actually works wonders, went from whine to complete silence. Who would of thought Toyota would try to pull this stunt on the fleet. That's why they don't recommend fluid changes. It's because Toyota ws (which corporate determined the fluid of choice) wears down too quickly as compared with the original fill(aisin ws). For people to do many east to west coast trips, this is important knowledge.. On the other hand, redline d6 is using a higher volume of additives to basestock oil which allows it to be more conductive, which prevents high heat static discharge. Static discharge is the reason behind gen1 copper winding coat failures. So the electrical current somewhat gets intermittently grounded not enough to set off a dtc, but enough to feel a minor burp in the electric motors. It also sounds like it's not healthy. Aisin is formulated kinda like only towards their transaxles only.
Update. I was able to have a one on one with an aisin tech and they mentioned that you need 1 quart of a proprietary 50w pure hydrotreated petroleum break-in fluid(Toyota 50w or Lucas oil stabilizer). The rest is aisin ws or Idemitsu Matic-J fluid(they're the same exact chemical formula and come from the same factory) You're welcome.
Baloney on the Redline. My car has been on Redline D6 for 13 years and 150,000 miles. Works perfect. And static discharge inside a trans full of trans fluid? Burping motors from shorts? Lol.......what complete nonsense. Windings blowout from extreme current loads pulled through them. High current and stalling the mg. Like flooring the car going up a steep hill with low battery power. G2s have under powered mgs unlike the g3 and on where power was greatly increased. Many people on this site have used all kinds of different trans fluid especially the lubegrard that has good reports. The trans could care less. G1 and G 2 windings don’t even touch the fluid. This has been proven with pictures on Weber automotive school on YouTube. The g3 and on do touch the fluid but doesn’t matter as the windings have extremely tough coatings and they greatly improved the iinverter cooling efficiency by using separate inverter rad. You should watch those you may learn something.