Too many variables Jim. That's why RV's don't have window stickers with EPA fuel mileage.

Used to see mileage on old carburated LE8's run as low as 3 MPG and, as high as 12 MPG on L29's (28 footer with 11,500 GVW)

8.1 is almost 50 Cu. In. more than your 7.... Login to read more.