Cold starting and CCS etc.

[CT8]

What do all the different cold CCS and MRV and pour tests etc. relate to in cold temperature performance? How do they relate. It is getting cold and I never really thought about how you could use the numbers and tests. Also how do syn vs "conventions" differ these days in extreme cold starting at any given viscosity , for example 10w30 Conventional vs 10w30 Syn base stock of choice..
Would a 10w syn be better than a 5W conventional?

 

[OilUzer]

I don't think synthetic has a different test spec than conventional. I assume any for example 5Wx30 oil has to pass the same tests including cold temp tests.

 

[OilUzer]

Also I think 10Wx is good down to 0°F and 5Wx down to -22°F if I recall correctly. I don't pay attention to ccs and mrv. They are for experts to discuss ....

 

[Shannow]

The specifications are the same for all oils, regardless of basestocks.

MRV is the ability of the oil to "fall" back into the pickup to replace the oil that has been pumped into the engine oil galleries.
CCS is the drag that's applied to the engine during starting because of the friction of the oil between engine components.

Pour point was formerly a part of the "W" testing but was dropped as being meaningless, and not representative of either the startability, nor the pumpability of the oil...so all the pour point tests of 5W at -40C are similarly meaningless, unless you are planning on changing the oil and getting it out of the bottle at these temperatures.

One thing, however.

Oils are allowed to "slip" a grade in the in service testing. So a 0W oil that slips to the viscometrics of a 5W in service still "passes".

This is where I personally believe (note, I have no proof) that synthetics are better in CCS/MRV, they are (in my belief) more likely to stay in their original grade.

 

[StevieC]

Originally Posted by Shannow
The specifications are the same for all oils, regardless of basestocks.

MRV is the ability of the oil to "fall" back into the pickup to replace the oil that has been pumped into the engine oil galleries.
CCS is the drag that's applied to the engine during starting because of the friction of the oil between engine components.

Pour point was formerly a part of the "W" testing but was dropped as being meaningless, and not representative of either the startability, nor the pumpability of the oil...so all the pour point tests of 5W at -40C are similarly meaningless, unless you are planning on changing the oil and getting it out of the bottle at these temperatures.

One thing, however.

Oils are allowed to "slip" a grade in the in service testing. So a 0W oil that slips to the viscometrics of a 5W in service still "passes".

This is where I personally believe (note, I have no proof) that synthetics are better in CCS/MRV, they are (in my belief) more likely to stay in their original grade.


Excellent explanation and I concur with your belief. I too have no proof but I find Synthetic is really tough to beat it out of what it once started as in a lot of categories when compared to conventional because of the better basestocks used and generally better additive package typically found in synthetics versus more economy conventional.

 

[madeej11]

Nobody likes a S..KUP

 

[Garak]

Originally Posted by CT8
Would a 10w syn be better than a 5W conventional?

No. Note that a 10w30 ILSAC would be better for CCS and MRV than a hypothetical 10w30 HDEO or A3/B3. Petro-Canada has some conventional ILSAC offerings that even beat their synthetic ILSAC offerings of the same grade, for reference. Slippage is another matter, of course. I do fine with 5w-XX here.

 

[dlundblad]

Originally Posted by OilUzer
Also I think 10Wx is good down to 0°F and 5Wx down to -22°F if I recall correctly. I don't pay attention to ccs and mrv. They are for experts to discuss ....

x2

If one stays up at night, they could use something like Mobil 1 Advanced Fuel Economy 0w30, but don't expect any noticeable differences in most continental US areas.

After seeing one guy here who thought his snow blower was easier to pull start around freezing with 0w30, I've lost faith in the "My car started easier" posters. A weak battery or starter could be and is most likely mistaken for too thick of oil.