Toyota W/S vs. Toyota IV

[exman123]

Hey all!

What is the difference between the 2 above? Last October the dealer put in Toyota IV while doing a flush on my Lexus GX470 when it needed W/S. I drove it about 250 miles with the IV in it and then they did another complete flush putting in the W/S.

Will that hurt anything?

 

[RF Overlord]

In 250 miles? No.

The primary differences are that WS (not W/S) is synthetic and has a lower, more shear-stable viscosity. This translates to marginally better fuel economy and a potential longer change interval.

 

[SOHCman]

Since this was october in kentucky, i doubt it was very cold which might have been an issue with the thicker toyota-IV. The ws is thinner and syn i believe, but its doubtfull you hurt anything, you just got a really good free trans flush!

 

[ctrcbob]

The T-IV is the fluid designed for the Aisen Warner transmissions. Many cars use the Aisen transmission including some Ford Fusions of a couple years back. Matter of fact, my 2011 MKZ uses the Aisen Warner. (Ford calls it their AWF-21 transmission)

 

[silverrat]

Originally Posted By: ctrcbob
The T-IV is the fluid designed for the Aisen Warner transmissions. Many cars use the Aisen transmission including some Ford Fusions of a couple years back. Matter of fact, my 2011 MKZ uses the Aisen Warner. (Ford calls it their AWF-21 transmission)



Okay those were some random facts but the OP also has an Aisin

 

[friendly_jacek]

Originally Posted By: RF Overlord

The primary differences are that WS (not W/S) is synthetic and has a lower, more shear-stable viscosity. This translates to marginally better fuel economy and a potential longer change interval.


Agree on the base oil difference. WS is not shear stable though and shears down to 4 cSt with some use.

The additive pack is identical as far one can tell from VOA.

 

[SOHCman]

Originally Posted By: friendly_jacek
Originally Posted By: RF Overlord

The primary differences are that WS (not W/S) is synthetic and has a lower, more shear-stable viscosity. This translates to marginally better fuel economy and a potential longer change interval.


Agree on the base oil difference. WS is not shear stable though and shears down to 4 cSt with some use.

The additive pack is identical as far one can tell from VOA.


How much use is "some use"?
The majority of members seem to be under the impression that WS is much more shear stable, and starts out thinner, but maintains grade much longer. Do you have a uoa showing the drop to 4 cst?

 

[JethroBodine]

WS is Toyota's new "World Standard" fluid for all AW transmissions. T-IV is the old spec.

 

[SXE10]

WS = World Standard, 5.4 cSt. T-IV = Toyota Type 4, 7.1 cSt @ 100 C

 

[Raybo]

WS fluid is not synthetic.

 

[HangFire]

I just read this thread carefully, and know no more than I did when I started.