For a 2000EX anything less than 4 hours at M0.8 plan on 2000lb/hr that will give you a bit of fat. 2000LX will give you a bit more but when I flew them there was no perf supplement yet approved for a machine with winglets. Reality with winglets is you will climb with less fuel used and your cruise FBO will drop but honestly it will not be anything overly significant that can get eaten up wx & tfc at destination. Given the regular number of hours flown by most business jets you wont even notice the fuel bills getting cheaper.
Depending upon routing, such as being held down due traffic I have seen burns as high as 2200lb first hour, flip side is I have seen burns as low as 1600lb/hr at F430in hour 5+.
2000lb/hr is a good rule of thumb @ M0.8
+16% if you want to do it at M0.82
+24% if you want to do it at M0.84
