All it takes is looking at the spec sheet on the 10w30 in question, or the back of the oil bottle. if it is also SN rated, it will have the low Phosphorous. The Schaeffer CK-4's on the approved list for Ford are not SN rated, so that seems to be the key in figuring out if a CK-4 10w30 has the higher phosphorous. I have noticed several CK-4's that aren't even listing gasoline engine ratings on their spec sheets now. That seems to be a pattern in this CK-4 game. No claim to gas engine rating and it will probably have the higher phosphorous.