The squealing I was referring to would be brakes.

And premium gas generally does very little for fuel economy.

Ethanol free may improve mileage & reduce wear to some degree, but outside of that 87 is generally fine unless your car is turbocharged or has a particularly high compression engine in it.

Fun fact, naturally aspirated rotary engines Rx8s will actually make more power on low octane because the long combustion chamber benefits from a faster flamefront. Personally confirmed this with dyno tests.