The figure dislayed in Cons is tank range at current riding speed / throtlle position at all times , it's Italian remember , it may stand for conservation , not consumption , who knows , fill up when the light comes on or at 100 miles , that definitely isn't rocket science
Here's another tip , the standard screen as fitted to 749R's (and presumably 999R's) is slightly higher and you can see the lights quite clearly add one of those to your wish list instead