Haven't got a clue as to how much fuel my B7100 uses per hour. Just know that when loaded on the PTO it uses a lot more than for loader or other light work. Usually run at the same RPM most of the time.
1/2 gallon an hour - how do you do that? I've a 3410 (GST), & usually run such at 2100-2400 rpm when brush cutting, leveling, etc. A gallon an hour for heavy work is about right for me.
My 3010 GST goes through about 1 gallon an hour when working it. It does seem like it uses more when using the loader even though when I use the loader the RPM's are kept about 2000