OT: springoy & ajol, para way lalis, here's what i found out:
(1) there are different types of octane ratings used in diff. parts of the world. there's the RON rating and there's also the MON rating.
the octane rating in NY is different from the octane rating used in the Phils. For example: 87 octane fuel, the "regular" gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as "regular", equivalent to 90-91 US (R+M)/2, and even deliver 98 (RON) or 100 (RON).
The octane rating may also be a "trade name", with the actual figure being higher than the nominal rating.
BOTTOMLINE: the higher octane rating, the higher the price.
(2) higher octane rating doesnt mean more mileage. its all about the autoignition resistance, anti-knocking capacity, and activation energies.
Engines perform best when using fuel with the octane rating for which they were designed and any increase in performance by using a fuel with a different octane rating is minimal or even imaginary, unless there are carbon hotspots, fuel injector clogging or other conditions that may cause a lean situation that can cause knocking that are more common in high mileage vehicles, which would cause modern cars to retard timing thus leading to a loss of both responsiveness and fuel economy.
Still, this is not all, there is a lot to discuss about "OCTANE RATING". Pls. refer to this link nalang:
http://en.wikipedia.org/wiki/Octane_rating
AS FOR THE PRICES, you have to study and compare the logistics difference from source to distribution, how they're being transported, cost of transportation, who are the players, extent of gov't intervention, etc. etc....before you analyze why the gas price is higher in one place while its much cheaper in another place.