Fuel System Cleaner, fuel injection cleaners, and stuff like that. Do they really work improve performance or just a waste of money?
To be honest, alot of them are full of malarkey, however I have experienced some pretty good effects with a few of the ones i've tried. A product called Z-Max is pretty good, I noticed around a 1mpg gain over my normal highway driving record mileage in my 2004 lexus IS300 when I used z-max. they recommend you use both parts to their system (oil and fuel) which I did. I didn't notice a gain in power (but i've got a KN intake and axle back exhaust already so it definitely moves quickly enough lol) I regularly use Lucas Oil's fuel system cleaner/stabilizer in my all of my vehicles as a preventative measure and so far haven't had any fuel system problems (knock on wood)
I drive a lot, I use a bottle of STP injector cleaner like twice a year. I don't see any great improvement, just see the same performance in a 100,000 mile engine that I see in a brand new one, that's enough for me. ( Plus, I can expense it !! )
Tow it, down the street, when he comes back tow it back.
I used to work at a shop where we did a lot of the fuel system cleaners and it helped a little. Mostly to rid the system of moisture, build up and clean it out. If your car has never had a fuel system cleaning I'd say go for it. As far as the gas tank additives, they are the same concept they help keep the tank and fuel injectors running smoother. If you perform a fuel system cleaning on your car the kit should come with a fuel tank additive.
