I know...ABABA type testing.
I am using about a years worth of SG driving on the exact route daily with appx the exact same driving and within 1mpg consistent results.
I did remove the mechanical fan this weekend and will do a couple days driving to test the results and get a new baseline. I will be installing an e-fan shortly (have all the parts) and then will retest with a more complete grille block that can be removed for some proper testing.
Already with the fan removed, the engine does rev more easily/quickly. I suspect that the fan clutch was bad.