I have a bottle of formula+ that says it is mineral base on the bottle. ? Doc
Sorry, I tend to use the term petroleum based. Others use the term mineral based.
It's Oil made by
CITGO. It works. I think it is to thick to use in the primary (IMO)
For Reference:
Group 1 - Conventional - Mineral oil derived from crude oil
Group 2 - Hydroprocessed - Highly refined mineral oil
Group 3 – Severe hydroprocessed - Ultra refined mineral oil
Group 4 – Full synthetics (chemically derived) - Chemically built Polyalphaolefins (PAO).
Group 5 - Based synthetics are usually not compatible with petroleum or petroleum fuels.
Groups 1 – 3 basestocks are derived from crude oil pumped from the ground whereas Group 4 basestocks are chemically derived, most often from ethylene gas, and contain none of the contaminants present in mineral oils.
Remember that Group III base stocks are considered synthetic motor oil only in the United States;any where else in the world they are not allowed to be marketed as "synthetic".