quote "I put two bottles of STP gas cleaner in every tank of gas and I have seen better gas milage every fillup"

the cost of 2 bottles of stp cleaner would nearly if not completely take away the cost benefit from extra mpg (maybe .5mpg if that). at probably $4 a bottle that would would be $8 a tank of gas just in cleaner. if you need cleaner on every tank of gas then something is probably wrong with your fuel system. i would say once a month or even once every couple of months would be ok to put one bottle of cleaner in but not 2 every tank of gas.

 

I have both and I get about 14mpg on my 01 with a 5.3. Problem is it sounds so good you are always goosing it to hear it so forget about better mileage! [X(][X(][X(][X(]