I've got a stock 2008 Suzuki SV650 with a cut can that got 69 mpg on the daily commute which is 90%. Changed to 5w40 Rotella synthetic and released some time in the first three gears and now are 70-71 mpg. I ride tucked most of the time and can up shift at 2000 rpms. Cruise is 5500-6000 rpms.
Got to love fuel injection and oxygen sensor!
I'm impressed with the gas mileage of the older bikes!
Norm