If I want to compare two brands of 10w30 on cold temp properties, it is easy because the CCS and MRV tests are at the same temperature. But if I want to compare oils with different front ("w") numbers, there seems to be no way and so I am left with only pour point.
One oil company rep told me you could use an oil down to about 10 degrees above pour point (can't remember if it was degrees F or C). But I heard pour point is not a very good way to evaluate an oil for winter use.
Also heard that CCS was not so good either because two oils could have the same CCS but one have a much lower MRV viscosity. Also that MRV reflects the extra thickening that can happen to an oil when it is cooled in a certain way (too fast or two slow, can't remembere).
Someone wrote on a post several months ago that they thought you could compare CCS viscosity by doubling the CCS viscosity for every 5 degrees C lower temperature. Wonder if that is true and whether there is such a simple rule of thumb for MRV?
Look at these two oils. They both look the same on pour point, but how to compare CCS and MRV?
oil 1: Valvoline Durablend 15w40
Pour point: -36C
CCS: 5700 @ -20C
MRV: 17000 @ -25C
Oil 2: Valvoline Maxlife 10w40
Pour point: -36
CCS: 7000 @ -25
MRV: 21,000 @ -30C
One oil company rep told me you could use an oil down to about 10 degrees above pour point (can't remember if it was degrees F or C). But I heard pour point is not a very good way to evaluate an oil for winter use.
Also heard that CCS was not so good either because two oils could have the same CCS but one have a much lower MRV viscosity. Also that MRV reflects the extra thickening that can happen to an oil when it is cooled in a certain way (too fast or two slow, can't remembere).
Someone wrote on a post several months ago that they thought you could compare CCS viscosity by doubling the CCS viscosity for every 5 degrees C lower temperature. Wonder if that is true and whether there is such a simple rule of thumb for MRV?
Look at these two oils. They both look the same on pour point, but how to compare CCS and MRV?
oil 1: Valvoline Durablend 15w40
Pour point: -36C
CCS: 5700 @ -20C
MRV: 17000 @ -25C
Oil 2: Valvoline Maxlife 10w40
Pour point: -36
CCS: 7000 @ -25
MRV: 21,000 @ -30C