well i thought i would post about schaffers fuel additive. i just got some the other day and i have to say there is nothing like it out there. i filled up the other day when the nozzle clicked off i put the additive in then topped off the tank. by the time i was done the idle had changed noticably it was MUCH smoother. since then i have seen smoother idle like mentioned some more power less smoke coming out of the whole less boost cruising down the road and 50 to 100 deg drop in egts i have yet to fill again so i dont know about milage though ive driven this tank harder then others so i dont think i wil see a change in the milage. all i have to say is schaffers fuel additive is the best.