Totally agree with the use of biofuel, but a lot of the stations I fill up at don't have biofuel or at least they don't advertise it on their pumps. The hot shots secrets works out to about $2 a tank. It's not a huge amount of added cost and I don't know if it works, but I have to have this truck last me a lot of miles so it is piece of mind using it. I do seem to get a little better fuel mileage when using it, .5 to 1 mpg better but you know it's pretty hard to get a true number since there can be so many variables involved.