mineral oil is natural,
synthetic is chemically made, and therefore is far more surperior in its molecule makeup,
sythetic oil is far better in reducing fricton, but sometimes thats not always wanted, ie in bike motors where the piston shares oil with the gearbox, cause the clutch relies on fricton.
thats why you should never run sythetic in a new engine, cause it works so well in reducing fricton it ont allow the rings/piston to bed in properly, which can result in a new engine losing power and burning oil from new,