So...
I have no idea how well it is really doing, but I do know that I have driven 104 miles so far and the needle is still in the white at the top of the gauge (at the bottom of the white but nonetheless). I believe that my federal VX registered in the same spot with 100 miles on the tank so I suspect I am still getting around 50 mpg or so even though it is a non-federal model. This is with no hyper-miling techniques, just a light throttle and mostly highway miles at 60-65 mph (90% hwy). I will see how it does for the entire tank, but so far I am fairly impressed. Plus this nice low-mileage VX is spoiling me
I am going to have to sell it before I fall in love with it.