i bought a STP(black bottle) fi. cleaner and i have some questions..
-how much is the MPG improvement?
-does it improves throttle even when it is not used?
-and any other info will be great
thanks

 

i did not really see any improvement using any on mine. it will be minimal at best. the main thing it will do is keep the injectors working correctly. but if your are really bad it might make a bigger improvement on yours

 

the STP stuff has made a difference on two of my friend's XJs. its essentially jet fuel with some detergents.

 

I just bought a 97 Jeep Cherokee with a 4.0 and it seems to miss just a little bit at idle, just enough to make the vehicle "twitch" a little every second or two. I thought about adding some fuel additive but then I remembered back to my last vehicle, a 97 VW Passat VR6. When I added fuel injector cleaner to my gastank somehow it blew past the rings and got into the oil pan and basically turned my oil into water. two weeks later the engine self-destructed. I looked on the VW forums and they all said never ever use fuel injector cleaner in VR6's or it will happen this way every time. I just wanted to check with people with more experience with Jeep engines and make sure that this wasn't going to be a re-run.

 

Never heard of fuel injection cleaner cause an engine to blow up but anything is possible.They make a fuel injector cleaner that is in a pressurized can they disabe the fuel pump and the engine runs off the fuel inj. cleaner it works really well.Only thing is you would have to find a repair shop with the equipment to do it.