My Mileage isnt that good but i didnt expect it to be. Hauling two 200plus pound Geezers around the sand with paddles at mostly full throttle all weekend got me 86 miles on 10 gallons.
I can guess others will chime in with ALOT better mileage.
Since we just got our X and we haven't even taken it out I can't really answer it on the the X, but I know that when we put the 800 Rotax in our Rhino we averaged over 16.1 miles to the gal in the sand with paddles over 3 consective weekends. and that was not babying it by any means, so if we get that with the X we will be very happy..