Eh, you might get something but nothing that will be noticable.
Knock sensor will detect when you put in low grade gas and the engine starts to detonate. Only real way to get a power boost from higher grade gas is to advance the timing of the car. Therefor you can take advantage of the higher flash point of the better gas.
What the rest said. But yes if you do get some bad gas or lower octane gas it will work with the computer system to retard the timing to prevent knock. My 1985 Caprice has such a thing and I never hear a thing out of it. And the time is advanced 2 degrees from where it should be. Where the 1981 without the sensor does occassionaly knock slightly in certain conditions. Never hear anything in the Equinox or moms Aveo. Can anybody tell me if these 2 have knock sensors or not?