75W140 oils misrepresented?

[Guzzigeezer]

To those more informed than me - what am I missing?
Looking at the manufacturer’s specs regarding 75W140 gear oils, specifically the 100*C rating in centistokes I find several that fall well within the SAE 90 range rather than 140 at the high end. Mobil 1 was the thinnest of all. At the other end is an Agip/Eni 85W140 that actually is a 75W140 . Seems like the manufacturers can just call it whatever they want. What gives?

 

[zrxkawboy]

Mobil lists Mobil 1 75W140 as 24.4 @ 100C. This is within the viscosity range for a xxW140 gear oil.

Mobil 1™ Syn Gear Lube LS 75W-140| Mobil™ Motor Oils

Discover how Mobil 1™ Syn Gear Lube LS 75W-140 provides supreme performance and vehicle gear protection.

www.mobil.com

 

[CarbonSteel]

To those more informed than me - what am I missing?
Looking at the manufacturer’s specs regarding 75W140 gear oils, specifically the 100*C rating in centistokes I find several that fall well within the SAE 90 range rather than 140 at the high end. Mobil 1 was the thinnest of all. At the other end is an Agip/Eni 85W140 that actually is a 75W140 . Seems like the manufacturers can just call it whatever they want. What gives?

Which do and what is the cSt number at 100°C?

 

[Guzzigeezer]

Mobil lists Mobil 1 75W140 as 24.4 @ 100C. This is within the viscosity range for a xxW140 gear oil.

Mobil 1™ Syn Gear Lube LS 75W-140| Mobil™ Motor Oils

Discover how Mobil 1™ Syn Gear Lube LS 75W-140 provides supreme performance and vehicle gear protection.

www.mobil.com

Doing further checking it seems the chart I was using is clearly wrong. Disregard everything I said and call me an idiot.

 

[zrxkawboy]

Doing further checking it seems the chart I was using is clearly wrong. Disregard everything I said and call me an idiot.

You're not an idiot. Sounds like you just ran across some wrong information. You asked, you learned...nothing wrong with that!

 

[DGXR]

Gear oil viscosities are not the same as engine oil viscosities, it's actually a different scale for cSt vs temp.
I don't know why it's done this way but I hope it helps.

 

[RooflessVW]

Doing further checking it seems the chart I was using is clearly wrong. Disregard everything I said and call me an idiot.

The chart you were using may have been before the introduction of 110 in 2005