Different viscosities same ATF application

[Neil Womack]

I think I need an education.

While reviewing Dexron III ATFs there seemed to be a wide viscosity range. Depending on the viscosity test used.

Three Dexron III rated ATF fluids all same manufacturer.
A> Pennzoil Dexron III ATF
B> Pennzoil Multi Vehicle ATF
C> Pennzoil Synthetic Blend ATF

All three had cSt @-40*C viscosity of 34.53, 35.00 & 35.85 respectively. These seem to have a very closely spaced variances. And to my uneducated eye that seems the way it ought to be with ATF.

All three had cP@40*C viscosity of 17200, 8600 and 9400 respectively. This measurement shows a very wide variance. Which seems odd to me for ATF.

I guess I do not know what is being tested with each of these tests. And more importantly should it matter to me or my transmission.

 

[SteveD2]

Different results between centistoke and centipoise due to different testing methods:
http://www.pumpworld.com/viscosity_measurements_centipoise.htm

http://www.pumpworld.com/viscosity_measurements_kinematic.htm

Now, who can explain just what it means to the end user?

Ken

 

[MolaKule]

The viscosity grade for Dexron III ATF is SAE 0W20.