Once every 6 months buy a bottle of rubbing alcohol 16 fl oz ($.98 at wal-mart) go to the gas station when you have half a take of gas. pour the WHOLE bottle of alcohol in the tank and then fil the tank with gas. run the tank just below 1/4 tank and fill it again.

It works better and is cheaper then buying injector cleaner at the parts store and it will give you a tempory LITTLE boost (not realy that noticable.)