Gas expected to be $4.00 a gallon come spring

They don't, however, make your gas any more powerful

That's where I'm getting at.

the only reason to use an octane booster is if your engine was designed for higher octane fuel than you put in it.

Yes, but like I said above, it's basically a waste of money. I seen on mythbusters that the common $4-5 bottle that "treats one tank of gas" only changed the level of the octane from 87 to roughly 87.4, and on another test with a small volume of gas it only went up to 87.9, so back to my orignal point you'd be better off getting the correct gas to begin with, or you'll need to purchase a few bottles of this.