We have seen this recently; you have to read the ratings on the container. Engine
oil has evolved in good and bad ways over the last 40 years.
Most of this ‘updating” to
oil formulations has been since 1993.
The oiling needs of the modern roller engines differ from the cleave bearing Flathead Ford V8, Y block , FE, and early Windsor.
When the last performance Windsor engines were produced by Ford, the
oil of choice was a specified API standard *SG* for the ’93 to ’95 cars.
Current motor oil has to walk a tight-rope as compared to years past, it hast to reduce friction and deal with semi exotic metals, high temperatures, etc.
Zinc was reduced due to the life reducing damage caused to Catalytic converters and oxygen sensors in the combustion and exhaust gas clearing process.
You know that your dear friends at the EPA are VERY interested in extending the life of a Catalytic converter to 120K+ miles.
API SG oil uses
zinc (ZDDP) as an anti-wear additive.
Note: Maximum phosphorus content per the API standard:
SG .12%
SM .08%
Look at the API notes on the container. -- it may be there on the fine print.
I think we are all in for specialty oils from now on as the API and the EPA keep messing with formulation.
Steve