JHardwick,
If you mean that it takes a few tank fulls for the Kleener to do it's thing then that is entirely possible as I never tested it again after the 30 miles. Maybe the improvements in mileage only occur after it has had a chance to do some cleaning in the engine?? I just figured the additive itself would create a more powerful combustion, or something, to provide immediate improvements in milage.
Given the amount of miles you drive, you would certainly be in a better position than I to know what works; I'm just passing along the results of my miniture experiment.
What I did was I got on the interstate, set the cruise, reset the overhead mpg once my speed was steady, and drove 30 miles (at night so there was no slowing down for traffic). Then I pulled over and put in the Kleener (even more than the minimum recommended), got back on the interstate set the cruise, reset the overhead again once my speed was steady, and checked the mileage right at 30 miles.
Same temperature, same humidity, same interstate, same sampling of diesel fuel, virtually identical terrain, same load, no acceleration or deceleration, no A/C, no idle time, no subtle differences in the amount of fuel put in during a "topping off" at the pump.
I know the overhead is not going to be correct about the mileage, but it is consistent. What I mean by that is if the overhead says I got 20 mpg when in reality hand calculation reveals I only got 19, the next time the overhead shows I got 20 mpg the hand calculations will still show 19 mpg.
I know 30 miles is not nearly enough to be scientific, but you would think there would at least be one-tenth of one mpg difference with the additive. It was exactly the same number.