When filling up last saturday night, with my usual BP ultimate at my usual store for the stupidly high usual price, I threw in 100mL of injector cleaner I got off my mechanic.

Since then, I've noticed my fuel consumption reading is up near the high 13's, sometimes down in the 12's too. Compare this to last week, average low 12's to even low 10/9's, and I've got myself one annoying little issue..

I thought to myself, surely it can't be this little amount of injector cleaner making the engine SO much cleaner that it gulps this much more fuel...can it? I'm just not sure if anything else has happened..Can someone shed some light onto this, if they've heard of/experienced similar things?