I made a comparison of the different gear oil weights since I was on the subject, though some here may be interested in seeing this info. There are more to compare but these were the ones I was interested in.

Note that the viscosity rating or "thickness" at a given temp is KV (Kinematic Viscosity)...Viscosity Index (VI) is a number to describe how much the oil temp shifts over a temperature range.

Higer KV, the "thicker" it runs at temp.
Higher VI, the more consistent its viscosity stays as it gets hotter.

The esther based Redline is about $62/gallon making almost as cheap as the likely-group 3/4-blend-definitelynotPAO-butstillimpressive Valvoline 75w140 which you can get at all major auto stores. The esther based Nismo and OSG fluids both cost you a quarter Kidney per bottle. Keep in mind if you are and advanced driver on track without a diff cooler you are almost certainly seeing sustained temps well above the KV@100C threshold. Actually even with a cooler the fluid still runs above that temperature.

 

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This is great information! Good job!

 

 

Thanks Mic!

Terras, lol good call already did it (updated the original pic)...didnt want to stop bc my goal was to find the KVs closes to the OSG oil. 190 weights seem to be the closest range.

 

I received this from OS Giken, ill try to find and update the chart with the oils below for comparisons. Obviously there is more going on than pure viscosity, and it seems the distinction is the addition, or lack thereof, of friction modifier to the lower weight oils, which when you see "N/S" (No Slip) is what it is referring to. Im pretty sure at least the first three listed contain no friction modifier, not sure about the Motorcraft. I spoke with them and with an oil cooler they said running 140 weight oil is just fine. Didnt seem too picky re: brand unlike the flyer below. I glanced at the rough oil weights recommended and they are right in line w/ the other 140 weights above in the KV@100c range.

 

Very nice. Thanks for all that information.

 

Thanks^ I updated the chart with the oils listed from OSG and some more notes.