Same with mine too. I use trip miles and fuel guage instead.
Mines the same to, fill it up and it gives you 180 miles 120 mileas later it still says 110 mileas then slowly drops down
had it remap at bmw . now when i fill it up it will only go to 13o miles and 130 later still full then go fast and then 30 miles left runout they ar rubbish
Having seen this thread, I now know I not dreaming. Full tank computer say >80 when it used to say >190. Goes up and down randomly rarely stable. Time for another recall me thinks
When I bought my F650GS twin I sold my previous bike. I took the guy out on a test ride following him on the BMW. I ran out of bloody fuel with 35 miles to go showing on the OBC!
I'll raise it with BMW as it's due for a service this week