driveshaft

[PARAGON]

Aside from Phil's question, I have a question more to the point. Why?

The biggest detractor to mileage is probably aero on a cross-country trip. Can't do a whole lot about that.

What is removing the front shaft going to accomplish? You still have friction drag from all of the front driveline components and the gears usually powering the front output shaft in the Tcase. The only thing you've done is remove some dead weight.