CCS = Cold-Cranking Simulator
Had to look this up..
Q: How Is a 0w30 oil with a ccs viscosity cP (D5293) @-35 degrees celcius with a rating of 3808 compare to one measured @ -20 with a ccs score of 5621?
"MotorOilEvaluator says:
The lower the temperature that an oil is tested at, the higher it’s CCS viscosity number will be, and a 5 degree difference can actually have a pretty significant effect on that number.
Thus, IF the numbers you provided in your question above are correct and not typos, the first oil is CONSIDERABLY better than the second, at least in regards to cold weather cranking. This is because, if the first oil had been tested at -20 degrees vs -35 degrees, it’s CCS value would actually be much lower than it already is at 3808.
Since the second oil is already considerably higher at 5621, the gap between the two would likely be even greater if both oils were tested at the same temperature.
That being said, be careful with this. It is not uncommon for spec sheets to have typos. A 0w30 oil MUST be tested at -35 degrees and achieve a CCS value of LESS than 6200 cP in order to be classified as a 0w oil. So, it’s possible that your 0w30 oil which indicates it was tested at -20, may actually have been tested at the required -35, but the PDS was typed up incorrectly.
Either way, even if the second oil was tested at -35, if the 5621 cP number is correct, then, the first oil is still better in cold temps.
Of course, that doesn’t say anything about it’s performance in hot temps or other stressful conditions – just cold temps."