Cold temp viscosity?

[Cyclops]

What was the reason that the cold temperature viscosity for multigrade motor oils was set at 40c? Seems like a strange temp as it's fairly warm. Why not 0c or at least something on par with room temp ~20c?

Doug

 

[flatlandtacoma]

Originally Posted By: Cyclops
What was the reason that the cold temperature viscosity for multigrade motor oils was set at 40c? Seems like a strange temp as it's fairly warm. Why not 0c or at least something on par with room temp ~20c?

Doug

It's not set at 40c. Where did you get that idea?

 

[rshunter]

Originally Posted By: flatlandtacoma
It's not set at 40c. Where did you get that idea?

He's thinking of the ASTM D445 test measurement standards...

 

[BobFout]

The winter-grade determination is done at -30C / -22F isn't it?

 

[flatlandtacoma]

Originally Posted By: BobFout
The winter-grade determination is done at -30C / -22F isn't it?

20W is -15C
15W is -20C
10W is -25C
5W is -30C

 

[BobFout]

Originally Posted By: flatlandtacoma
Originally Posted By: BobFout
The winter-grade determination is done at -30C / -22F isn't it?

20W is -15C
15W is -20C
10W is -25C
5W is -30C




Ah thanks! And 0w?

 

[edhackett]

The above is for cranking.

OW would be -35

ASTM D 4684, Cold Pumping degrees C is:

0W -40
5W -35
10W -30
15W -25
20W -20

Ed

 

[rshunter]

Viscosity Grade - Cranking (mPa.s) max @ temp °C

0W ------------------ 6200 @ -35
5W ------------------ 6600 @ -30
10W ---------------- 7000 @ -25
15W ---------------- 7000 @ -20
20W ---------------- 9500 @ -15
25W ---------------- 13,000 @ -10

 

[Cyclops]

Thanks guys! I havta admit being confused over the cold (w)viscosity determination of multigrade oils. I thought the cold viscosity was measured at 40c.

Doug

 

[unDummy]

Its a pdf and even mentions the ASTM test number for each test. Google the ASTM test # for info.

There are max, min, and range requirements.

 

[unDummy]

Originally Posted By: unDummy


Its a pdf and even mentions the ASTM test number for each test. Google the ASTM test # for info.

There are max, min, and range requirements.


Not sure what happened to the link. But, you can google sae j300.

SAE J300

 

[Bazz54]

Originally Posted By: Cyclops
What was the reason that the cold temperature viscosity for multigrade motor oils was set at 40c? Seems like a strange temp as it's fairly warm. Why not 0c or at least something on par with room temp ~20c?

Doug


Not sure why, but here in Europe, most data sheets do quote viscosity values only at 40 and 100'C.