Quite expected for 500 cc single cylinder, especially on highway.
It's a lot worse then most others I've read about or ridden myself.
I got 25km/l on the Peugeot Satelis 500 (piaggio master 493cc engine) which
is as heavy as the Xciting 500, and I wasn't actually going slow.
Throttle pinned on most corner exits, braking hard, then pinned again.
4l/100km exactly.
BTW, I'm selling my Kawasaki and will probably buy either the Xciting 500Ri or
the Yamaha Majesty 400..