Hey bitogers! I just wanted to report that I have a high mileage (210k) 00 Nissan Sentra and decided to add a full can of Chemtool to a little under a half tank of gas. This would be somewhere in the ballpark of 5-7 gallons of gas. So far the car is running much smoother and I plan on running the gas down until the low fuel indicator light comes on then fill the tank completely. Now bear in mind I always use Shell gas as I like to stay top tier. I have searched the forums and see the recommendations for adding to a 1/4 tank then filling up due to the harshness of the solvents. Now I added this to my dads van last weekend on the trip to Talladega, he had no clue about it, and he said that the van's gained a little more than 1 mpg. Driveability has not changed, but, it was enough for him to notice. Does anyone else have experience running a very concentrated dose of this stuff in their fuel? If so mind sharing your experiences?