Fuel additives do not work.
When they say that an octane booster will raise it a point, this is not from 91 to 92, its a completely different number they are talking about.
The only effective way to raise your octane with an aditive, is to do one of the following.
1. Dump in a few gallons of toluene
2. Dump in a good deal of Torco octane booster... more than that puny little bottle you buy at Kragen
3. Add a few gallons of real race fuel.
However, unless you are running forced induction, or have raised your compression, you will not get any power boost out of a higher octane fuel.
Octane essentially is a measurement of a fuels ability to resist pre-detonation. This is important on forced induction motors, tubo, supercharged, or nitrous fed, etc, or high compression motors.
It does not give you more power, it simply allows you to run your engine harder, without blowing it up. Higher octane fuel is actually harder to ignite. What you want for maximum performance, is the lowest octane fuel, that you engine can run without damaging itself.
The best fuel cleaner, is you fuel filter.
If you want to play around with fluids for more performance, dont look to your fuel system, look to your vacume system, your oil system, and your transmission and differential fluids.
In my 1995 BMW M3, I cleaned out my vacume system using Seafoam sucked into the system, with mind bogglingly good results. However, your car is probably not old enough to need such a treatment.
Techron does work in keeping your engine clean, but if you want it, simply use Chevron premium gasoline... which you should already be using my opinion actually... as I belive it to be the best gasoline out there. You can always dump it in later, but you will not see the same results from one large does of Techron to the fuel, as you would from using it regularly via the gasoline.
This test is far less technical than what I was talking about, but it will give you an idea. Basically a British TV show dumped fuel adititves into a Rover motor... not exactally a high strung Maserati motor... but you will see that they all do nothing, or reduce power.
http://youtube.com/watch?v=2jbcCr2ll3c
-Colleen