When I had the 650 (naked k5 with de-baffled Scorpion can) I used to get 43 mpg around London
When running it in I managed to get 62mpg, but never anywhere near that afterwards
I ran it completely dry so it conked out (twice
) , and both times only ever managed to get 14.2 litres in the tank, and that was holding the bike upright not on the sidestand, so I don't believe Mr Suzuki when he says the tank holds 17 litres
On the SV1000 I'm averaging 50mpg - thats on a 100 mile a day mostly Motorway (M25/M40/A3) commute
I've seen 157 miles out of a tankful, but reckon that was pretty close
Low fuel light usually comes on around 130 these days