no, gas treatment ups the grade of the gas you use 1-2 grades. so if u use 87 or 89 you'll have 89 or 91 which is like using premium gas. it will run smoother and could posible add a few horse. but nothing too drastic. some brands are a waste of money, make sure the treatment says Made with Jet Fuel.
On a fill up using the treatment is probably cheaper than buying the higher octane fuel at the pump. Think about it, the difference between regular and high test is what, $.20-$.30? On a 20 gallon fill that's $6. How much is the treatment? See my point?