Two-stroke, has a base oil, & additives, [ one or two components] or multiple components, depending on the demand of the oil,, [ hi temp ,race,]
theres 3 kinds of base, synthetic/ mineral/ vegitable. synthetic are petroleum based,
V,I. [ viscosity index] is measure of thikening at low temp. higher the number the less likely to change at exterme temps.
Low-ash, is detergents added, to stop hydrocarbons build up. [ a must for power valve engines,,]
any oil with code,, API- TC. Is fine you"l find this on back of bottle ..
Some oils [ thick] like Castrol R40 & Shell SX [mineral] are for pre- mix ,,
Simples eh,,,