Just to keep you up to date, I bought a new 650 Silverado, so far the fuel economy has been good, I have noticed a steady increase in power and economy as I start to clock up some mileage, I am up to an average of 60 Mpg, my journey to work is 20% (30 Mph) small roads, 30% (40 Mph) urban roads and 50% motorway (65-70 Mph). I travel about 50 miles a day. In short, it depends on how you ride this bike but it is a very economical machine. Alan McDonald Smith