It works in conjunction with the fuel light instead of a reserve tap on your tank , once the low fuel light comes on the Battery / Air temp / Cons display will only show Cons , or mileage left in the tank at your current speed / throttle position.
You will notice that the figure changes as you go slower or faster indicating the different tank range left at your current speed.
Best bet is fill up every 100 miles (the fuel light came on at around 90 miles on my 999S) , or buy a 749R and get a proper size tank
