transmission fluid question

i would stick with toyota. it's not much more, and you change it so infrequently. how many miles on your car, and has it ever been changed?

 

okay. the prius transaxle is a bit different from most, so i'll defer to the experts. all the best.

 

You may just be fine. Still, I open the Owner's Manual, and read stuff like this, in the 2004 Owner's Manual:



And then in later Owner's Manual, my 2010 for example:



If it was me, I'd buy 12 quarts, do a change, drive for a day, do a change, drive for a day, do a change, chalk it up to experience. But that's just me: lots of folks intentionally use an alternative fluid.

 

I would just use real Toyota ATF WS in 90,000* miles when I did the next change.

* there is no official change interval, so you are free to make up your own. I use 30,000, then 90,000, then every 90,000. The point is to change it every so often to clean out suspended solids.

 

I would not.

From the Valvoline website: http://content.valvoline.com/pdf/maxlife_atf.pdf

"Valvoline has conducted extensive in-house testing, independent lab testing, and field-testing to support MaxLife ATF performance in the broadest range of transmissions; however, it should be noted that MaxLife ATF is not a OEM licensed product. The respective vehicle manufacturers have neither evaluated nor endorsed MaxLife ATF in these applications."

Valvoline claims that this fluid will substitute for Toyota/Lexus Type T, T III, T IV and WS. Not to mention many other ATF specified by other manufacturers.

I have had occasion to use both Toyota ATF T IV and WS because Classic Prius is spec'd with T IV. There is a very noticeable viscosity difference between the two; WS is much thinner. I am highly skeptical of a claim that one fluid can work well in both applications.

If it were really true that one ATF formulation could fully substitute for four Toyota ATFs, then Toyota would have switched to that ATF.

 

Over a year past since you posted about this. I'm wondering if you kept the MaxLife in your 04? If so, how did your Prius preform? Any averse effects?