Originally Posted By: friendly_jacek
Originally Posted By: Bandito440
Do a Google search for Toyota WS MSDS and read my threads:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2716151
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2762666
There's a copy of the WS MSDS floating around the intertubes somewhere that shows its base to be mineral. I'm not entirely sure myself, but it seems pretty lackluster. I suggest flushing it at 60k.
I used to believe WS was inferior fluid optimized for fuel efficiency, but not anymore.
Why?
1. I read SAE papers about low viscosity ATF development by Toyota and wear control was a big priority there. They had to jump through a few hoops to provide for wear control in lower viscosity fluid.
2. I compared UOA results in WS vs T-IV in same or similar trannies. No difference I could see in wear results/mile.
3. Toyota warns in their TSB that WS is hygroscopic. That can only mean only one thing: esters.
As for the MSDS, They are commonly incorrect. QSUD's MSDS states 100% PAO for some weights. We know that is impossible.
Some good research you've done here. My biggest problem with WS is the cost. It's $10/qt at all of the dealers near me, and the analysis reports that I looked at made it seem... blah. Not poor, but not worth the cost. The flush on my Tacoma cost me $70 using Maxlife that is labeled synthetic. WS would have been $140, and the dealer service was $300. I'm happy with the performance. I've got 9,000 miles on it now.