It Died on Me

for what it's worth i use the trip 2 for mileage and just reset every time i fill up.
 
I can't remember the last bike I owned where I trusted the fuel gauge...always used the odometer. Besides...my old a$$ needs to get off and walk around at about the 150 mile mark
 
I just ride by the trip meter. When the light comes on ,you have almost a 1/3 of a tank left. I like the advanced warning because fuel stops here are often 100-200klms.

Looking around the net there is all sorts of fuel capacities listed but for the R3 it is probably 24 useable litres with approx a litre left when it stops.