I flew the 800XP for a few hundred hours and found it to be an extremely versatile airplane. We normally cruised at .77 Mach, or about 440 KTAS average. At this speed, the practical range starting with 10,000 lbs and 2,000 lbs. fuel remaining at destination would be about 2,000 nm equivalent still air distance (ESAD). The winds aloft may of course affect your altitude and cruise speed selection. A typical hourly fuel burn profile for a nominal 5 hour trip like this would be something very close to the following:
1st hour - 2,000# (FL350-370)
2nd hour - 1,600# (FL370-390
3rd hour - 1,500# (FL380-400)
4th hour - 1,400# (FL390-410)
5th hour - 1,300# (FL400-410 for part of the hour, then descent)
Allowing for APU burn, start/taxi and descent fuel, the above is a ballpark approximation, but fairly reliable for planning purposes. Obviously, any requirement to fly a greater ESAD would require a closer look and may involve reducing both the cruise speed and the planned fuel remaining upon arrival. For an overland flight to a forecast VFR destination, I planned no less than 1,200 lbs. Weather and available suitable alternates often dictated a greater reserve than that.
I did have a few occasions when it was necessary to fly the long range cruise profile of 400 KTAS. My longest flight of this sort was 6 hours 46 minutes and left me with 900 lbs of fuel after shutdown. The APU was not used. I had it planned for 6:36 and 8,600 lbs (plus taxi fuel) to a VFR wx forecast, but of course we ended up with conditions not at all conducive to a visual approach and had fly an extra 10 minutes and 300 lbs to shoot the ILS! According to the flight summary page on the FMS, 2,450 nautical air miles and 2,200 track miles were flown on 8,900 lbs of fuel. The other 200 lbs were used for taxiing.
Flying the long range cruise profile, (pre-US DRVSM) the fuel burn profile looked like this:
1st hour - 1,800# (FL350)
2nd hour - 1,400# (wrong way FL370)
3rd hour - 1,300# (FL390)
4th hour - 1,300# (part of hour wrong way FL410)
5th hour - 1,200# (Fl410)
6th hour - 1,100# (FL410)
.75 of 7th hour - 800# (negotiated late descent, ILS approach and landing)
If circumstances require you to plan for 1,800 - 2,000 lbs fuel or so at destination, 6 hours and about 2,200 nm ESAD is a fairly accurate "off the top of your head" planning maximum. I used Universal W&A for all longer range flights and double checked their data against mine. Their 800XP perf data was usually spot on if you flew the profile accurately. Always better to fly it 5 kts too fast than 5 kts too slow though.
The after market winglet equipped Hawker 800XPs are apparently capable of an additional 150 miles or so from what I hear. I have not yet flown one so equipped myself though.
I hope the above info is useful.
Best regards,
Westhawk