Next time you are in Dallas, feel free to come visit. The fact remains that at 75mph, the XJ6 is getting 24mpg, and at 55 it gets 19-20.
OHHHH! We arn't talking 1972 GTO, are we? ;-D
That explains it and I fully agree. I drive a Camaro with a 6 speed. At 55 I am in 5th turning high rpms (around 3000), but at 75 I am in 6th turning around 1800 in a ratio IIRC of .75:1. Much more efficient and the only time I approach over 20 MPG.