[thstone]

My first thoughts are that real world driving has too many variables that can cause the mpg's to vary, especially if you're trying to account for a few percent difference. You'd have to drive the same route at the same time of year in similar traffic with the cruise control set to the same speed in the same places to get an apples to apples comparison that would allow you to try to isolate the change in mpg due to the change in tranny fluid.

Whatever change that the trans fluid had on the mpg's is most likely masked by all of the real world variables that are probably much larger contributors to a difference in mpg.