First of all. US octane rating dont match up with Pakistan rating. so link using HI octane word wont fit for a Pk user.
2ndly, Most modern engine use cleaner fuel for less waste, polution. so recently compression ratio has been raised in new engine designs.
3rdly, Octane will keep fueling system cleaner in yr car.
4rth For racing purpose octane mixed with pure fuel with give best result.
5th For economy octane or unleaded fuel mixed with octane will lower yr maintance budget.