Hobc in Pakistan has been prone to manganese addition and due to that, it can damage cat converters. M not sure about advanced or not, standard is now 91 ron here..my friends work at senior post in shell and they told that 91 ron is followed as a standard. Hobc with manganese can be a problem.. remember what happened with Civic turbo. Slight increase in mileage could ne there but i think hobc being unregulated is not a wise option, unless absolutely required.