I just added a bottle of Red Line SI-1 to my tank, and began to wonder about the concentration vs effectiveness. Do you think that a full bottle mixed with 10 gallons of gas cleans as well as a full bottle mixed with 20 gallons of gas? Given that question, I wonder if I would achieve better cleaning by adding 2 bottles to my 20 gallon tank? Maybe doing 2 back to back applications would be better?