I check the gas mileage once or twice a year. Mileage has been typically in the 47-49 mpg range over the years. A bit lower with spirited/high speed riding, and a bit higher with a light throttle. I've not seen much change with the introduction of ethanol-laced fuel, although cold starts are most affected.
'73 R60/5 Toaster
Luddite. Not just a philosophy, a way of life...