just remember, "points" on those cans are most of teh time TENTHS of octane. "5 points!" means .5 octane.
Of course, most of em are even over spec'd at that. Also they're not always clean burning. Also, they don't do shit anyway unless your car is tuned to use the higher effective octane.
If you put in 14 gallons of 92 and want 93 out of, say, a 12 oz can? The shit in there better be 242 octane. That's 1 octane boost. Most of the shit in the cans ain't 242 octane, I assure you. If you want regular gas to be like race gas from a can (say 14 gallons of 93 into 100 octane from a 12oz can), it'd have to be an eye poppingly ridiculous 1146 octane.
2015 STi: Still Stock
04 STi, 04 WRX: SOLD