Originally Posted By: SR5
Joe, always good to hear from you.
In the PQIA VOA analysis above Valvoline SynPower has 2100 ppm Ca, 460 ppm Na, and no Mg or Mo. So much more Ca than Na. The Royal Purple is much the same.
So do you think the Na is a friction modifier or part of the TBN over base ?
These VOA are 3 years old, and I suspect both Valvoline and RP have been using Na for much longer than that, so it must be sorted to some degree.
The rep that valvoline has on the street around me is that it's slippery/low friction oil, but the TBN depletes a bit quicker than most.
It's always hard to be precise but 2013 ppm of Calcium metal is roughly equivalent to 1.7% of 300 TBN Calcium Sulphonate so this would put 5.1 TBN into the oil. Say the oil contains about 5% of 20 TBN ashless dispersant so there's another 1 TBN. Hard to estimate how much 135 TBN diphenyl amine AO is in this specific oil but for the sake of argument, say 1.0% so there's another 1.35 TBN taking the total up to roughly 6.9 TBN out of a measured total of 7.9.
So, yes, I guess whatever sodium compound is in this oil is contributing to TBN but a minor amount relative to other sources. I'm currently working through an old 1997 Lubrizol patent on sodium additives that might throw some light on what this stuff is and what it's functions are.
PS - I should have added that a lot of these types of compounds contain nitrogen because they start their reactive life as alkyl amines which are basic (alkaline). That the sodium salt might be basic should therefore come as no surprise.
Joe, always good to hear from you.
In the PQIA VOA analysis above Valvoline SynPower has 2100 ppm Ca, 460 ppm Na, and no Mg or Mo. So much more Ca than Na. The Royal Purple is much the same.
So do you think the Na is a friction modifier or part of the TBN over base ?
These VOA are 3 years old, and I suspect both Valvoline and RP have been using Na for much longer than that, so it must be sorted to some degree.
The rep that valvoline has on the street around me is that it's slippery/low friction oil, but the TBN depletes a bit quicker than most.
It's always hard to be precise but 2013 ppm of Calcium metal is roughly equivalent to 1.7% of 300 TBN Calcium Sulphonate so this would put 5.1 TBN into the oil. Say the oil contains about 5% of 20 TBN ashless dispersant so there's another 1 TBN. Hard to estimate how much 135 TBN diphenyl amine AO is in this specific oil but for the sake of argument, say 1.0% so there's another 1.35 TBN taking the total up to roughly 6.9 TBN out of a measured total of 7.9.
So, yes, I guess whatever sodium compound is in this oil is contributing to TBN but a minor amount relative to other sources. I'm currently working through an old 1997 Lubrizol patent on sodium additives that might throw some light on what this stuff is and what it's functions are.
PS - I should have added that a lot of these types of compounds contain nitrogen because they start their reactive life as alkyl amines which are basic (alkaline). That the sodium salt might be basic should therefore come as no surprise.
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