I read that running the gas tank dry too often can damage the catalytic convertor because it would allow the wrong exhaust (fuel?) and air mixture in the cat. I do not understand it. I did not know that it could damage the pump.
The lowest I ever got on fuel was when the display told me I had 9 miles left and it took 3.96 US gallons to fill the tank. According to the BMW website, the F900XR has 4.1 US gallons (3.4 UK Gallons or 15.5 Liters) of Usable Tank Volume. That tank took me 209 miles (336 Km) so I assume 200 miles per tank at my average consumption of 55 MPG US (66 MPG UK or 4.28 l/100Km).
I use regular gas which has 87 octane (AKI). That's what the American owner's manual recommends.