Hey Dave,
I've had varying mpg's, but usually because I'm not on top of my tire pressure. My best is 88mpg as of two fill-ups ago. I'm averaging close to 80 mpg's for the nearly 2600 miles that I've owned mine (bought with zero miles from dealer). It's a great scooter.
One thing I have noticed, is that if I'm doing any sort of distance and keeping the mph around 55, my mileage is a hell of a lot better. I live in Vermont, though, so I'm not dealing with the thin air here at all.
Keep things posted on your average. Use fuelly.com, and use their banner, too, so you can always have it updated at the bottom of your postings.
The nice thing is, once the scoot is broken in, the mpg's should be consistent and somewhat improved (though nothing to write home about).
PBAS