Confusing is hardly the word for it Tex. Rear drives have always confused me because the Higher the numerical number is the Lower your gear is. You would think that a taller tire would get you better mileage (which it does) but it doesn't seem like it because your math gets screwed up because of the skewed odometer readings. In all actuality I belive you get better mileage with taller tires because you're raising your gear ratio. This may be offset by the fact the engine is not designed to run at the lower RPM range but who knows....

 

Well in town, my Alpha gets 11.3 MPG and to Vegas (cruise set at 70 MPH) I got 17.1 MPG.