Originally Posted By: Rex
http://www.pqiamerica.com/March2013PCMO/supertech.htm
I suppose a manufacturer adds an additional additive or two, given their oil more of "something" which justifies the cost increase.
The difference goes well beyond an additive or two and extends to the quality of the basestock blend used, as evidenced by the relative performance of M1 and ST in the PQIA VOA series you've linked to.
Compare the M1 5W-30 to the ST 5W-30 in this same series of PQIA VOAs. The oils were bought on the same date probably on the same shopping trip to a NJ Walmart.
The M1 has higher TBN, a higher VI, lower NOACK and significantly lower viscosity at -30C as compared to the ST.
Additives?
The M1 has a balanced detergency package consisting of both calcium and magnesium while the ST relies upon calcium alone.
Both oils have a nice dose of boron, but only the M1 has a similar dose of moly, the ST having none.
Whether you look at physical characteristics or additive package, both as measured by an objective third party, the ST clearly lags the M1.
Does this make the M1 the better oil for the average family beater?
In terms of engine cleanliness, cold weather starts as well as reduced friction in the mixed or boundry layer regimes, I'd say that it does.
Is it worth another five or six bucks once or twice a year?
That's a matter of personal choice and personal priorities, but nobody can accurately state that ST is every bit as good as M1 when the objective results show otherwise.
http://www.pqiamerica.com/March2013PCMO/supertech.htm
I suppose a manufacturer adds an additional additive or two, given their oil more of "something" which justifies the cost increase.
The difference goes well beyond an additive or two and extends to the quality of the basestock blend used, as evidenced by the relative performance of M1 and ST in the PQIA VOA series you've linked to.
Compare the M1 5W-30 to the ST 5W-30 in this same series of PQIA VOAs. The oils were bought on the same date probably on the same shopping trip to a NJ Walmart.
The M1 has higher TBN, a higher VI, lower NOACK and significantly lower viscosity at -30C as compared to the ST.
Additives?
The M1 has a balanced detergency package consisting of both calcium and magnesium while the ST relies upon calcium alone.
Both oils have a nice dose of boron, but only the M1 has a similar dose of moly, the ST having none.
Whether you look at physical characteristics or additive package, both as measured by an objective third party, the ST clearly lags the M1.
Does this make the M1 the better oil for the average family beater?
In terms of engine cleanliness, cold weather starts as well as reduced friction in the mixed or boundry layer regimes, I'd say that it does.
Is it worth another five or six bucks once or twice a year?
That's a matter of personal choice and personal priorities, but nobody can accurately state that ST is every bit as good as M1 when the objective results show otherwise.