So now that I've got some time on my 9R XCR & had a chance to compare the fuel mileage to my wife's '23 650 Indy Adventure I thought I'd share what I found. We rode trails & lakes yesterday from Port Loring to Dunchurch for 45 miles (72km) and then filled both sleds back up;
9R XCR 136 - 18.5 litres
650 Indy Adventure 137 - 14.2 litres
I was running harder on the lakes & playing a bit out in the powder that's on the lakes there with all the recent snowfall. I have to be honest I am quite happy at the fuel mileage of my 9R. I don't think the 9R uses that much more fuel over the 850. My 850 was always within a litre of my friends 850 XRS.