The Mobil Jet 387 referenced in the opening post is a 4th generation jet turbine engine oil and is completely different from piston aircraft engine oil. Jet turbine engine oils are based entirely on polyol esters (93-96%) and contain mainly anti-oxidants, anti-wear, and anti-corrosion additives, and sometime a dash of anti-foam, EP, and other additives. They have no detergents, dispersants, or organometallic additives. They are very light oils, thinner than 0W-20s.
Piston aircraft engine oils are much thicker, often XW-50s, and are based on mineral oils, sometimes blended with PAO. Additives are mainly dispersants, anti-oxidants, and anti-corrosion with no organometallic additives.
Neither are suitable for automotive engines. They contain no detergents or ZDDP, and the jet oils typically have a phosphorus content of 0.18-0.24%.
Tom NJ