Transmission fluid, which is thinner Amsoil or M1

[302Xplorer]

My 2000 Ford Explorer 5.0/AWD is fast approaching 100K. I am going to be changing out all of the fluids transmission, T/C, front and rear differentials.
I am going to be running the lightest (viscosity) fluids all around. I understand how to tell w/ most all fluids, but am stumped as to how to tell w/ transmission fluid, any help would be appreciated.

-302X

 

[brian12]

I know M1 has a viscosity of 7.4. Can't tell you about Amsoil. You could always go to their website and look at their product data sheet.

 

[302Xplorer]

Here is the data.
It looks like Amsoil is the thinner of the two.

AMSOIL Synthetic Universal Automatic Transmission Fluid (ATF)
Kinematic Viscosity @ 100°C, cSt (ASTM D-445) 6.8
Kinematic Viscosity @ 40°C, cSt (ASTM D-445) 32.4
Viscosity Index (ASTM D-2270) 172
Noack Volatility, % weight loss (ASTM D-5800) 11.0
Flash Point °C (°F) (ASTM D-92) 220 (428)


Mobil 1 Synthetic
ATF
Viscosity, ASTM D 445
cSt @ 40º C 36.3
cSt @ 100º C 7.4
Viscosity Index, ASTM D 2270 176
Pour Point, ºC, ASTM D 97 -41C
Flash Point, ºC, ASTM D 92 200

 

[Steve S]

I would go for the highest viscosity .

 

[PandaBear]

Toyota WS is the thinnest I know, but may not be for your application.

 

[Ken2]

Originally Posted By: 302Xplorer
I am going to be running the lightest (viscosity) fluids all around.

Why?

In machinery with some wear in the parts, higher viscosity lubes are needed in these bigger clearances.

Licensed ATFs must meet exacting viscosity specs from the licensors. One signigicant difference between GM's Dexron-III and Dexron-VI, for example, is the lighter viscosity of Dex-VI. There are other important differences.

The near-universal fluids don't meet many of the specific viscosity specs but are close enough to work well.

 

[AzFireGuy79]

Redline D6 has a viscosity of 6.4 which is slightly more than the WS and will work where DEX VI is required.

 

[Whitewolf]

Originally Posted By: 302Xplorer
My 2000 Ford Explorer 5.0/AWD is fast approaching 100K. I am going to be changing out all of the fluids transmission, T/C, front and rear differentials.
I am going to be running the lightest (viscosity) fluids all around. I understand how to tell w/ most all fluids, but am stumped as to how to tell w/ transmission fluid, any help would be appreciated.

-302X


The problem is that running lighter viscosity is ok within reason as long as the fluid is shear stable. Older ATFs used to traditionally have a new oil viscosity of somewhere in the region of 7.5-8.0 cSt (KV/100'C). The problem is that they used to shear like crazy ~ and end up at about 80,000 miles with a KV/100 of 4.1/4.2 cSt. The newer, well formulated fluids start off at a lower vis. of about 6.0 cSt but they are much more shear resistant so even after 100,000 miles, they will still be around 5.3-5.2 cSt KV/100.
Does this comment help at all?

 

[bruce381]

just tell him to run Dex 6 or mec SP/LV LOL
bruce