Funny, same here and mine always had a sidecar and lived in the hills so should have more of a thirst. The 550k3 was better for economy, but that was most noticeable on motorways where it seemed to run off fresh air. On A roads it used almost exactly the same amount as my mates 250 superdream, to the penny at fuel stops. My ntv 650 is definitely more economical. I found smaller bikes eg Suzuki fz50 and gs125 were phenomenally frugal transport, appart from on hilly routes. As far as I could tell my ntv 650 would rank as my most economical bike ever living out in the hills of mid Wales. It could be a thirsty beast if thrashed, hard braking and acceleration etc but you could just as well go pretty fast but ride smoothly and get great economy.