various types of petrol available, their efficiency and composition?

Question

petrols like:speed 97, power, power 93....

Answer 1

Well, most of what is in them is plain old gasoline. The ones with higher octane numbers have been adjusted to reduce knock in high compression engines. High compression engines squeeze the air-fuel mixture more to get more power out of it. Using high octane gasoline in a lower compression engine that does not call for it wastes the money paid.
Also added are detergents and other chemicals that keep carb jets and injectors clean and help control moisture in the fuel and tank.