"Oil pressure is also directly related to flow volume. Synthetic oil is more uniform in molecular structure and provides less resistance to flow therefore in order to achieve the same flow volume as a petroleum oil, which has a higher frictional resistance to flow, it is possible that under some conditions, such as idling that a slightly lower oil pressure could be noticed"
this is from a book titled "motor oils and lubrication" .what is the pressure specification at idle anyways? i checked the fordtechservice.com (for which i know the username and password
) and i looked at the oil pressure specs for a 94-95 sc. spec is 40-60 psi @ 2500 rpm with engine at operating temp. doesnt go back to the 89-93 years but i would assume that they are spec'd for slightly lower oil pressure since the 94-95's had a higher capacity oil pump.ford actually thinks that 7 psi is good at idle, so i would think that 20 psi is good oil pressure, if your engine produces 40-60 psi at 2500rpm then who cares what the idle oil pressure is.