Fuel consumption is such an interesting topic.
Even when I ride with another bud on the exact same sled, we burn different amounts of fuel. Everyone modulates throttle differently, and so many little nuances make the difference.
My turbo 850 doo burns roughly the same amount of fuel as a non turbo doo on an average day, but I think it's because I need less throttle to achieve the same track speed as a N/A with all things equal.
When it's deep and everyone is just pinned the whole time, the turbo burns more gas.
But I have a bud on an axys 850 that always burns a gallon more than everyone, so like we always say on the internet: YMMV!