So as not to make this post seem like a commercial, I won't mention the brands; but if readers are considering powered two wheels; are interested in the mid-size range; and demand at least decent mpg in a bike at a decent price, there are now two, proven motorcycle power trains with exceptional mpg as compared to the rivals. One is a 670 cc parallel twin with a rev limit at a very low 6500 that uses regular gas, is available in three bike types; straight shift or auto choice for each type, starting below $7000 new; low maintenance schedule except chain, and mpg listed as high as 64, but I easily achieve greater than 75 in warm weather commuting in a CTX700 version.
The second is a single 652, listed over 70 at 55 mph constant, proven upper 60s in real-world conservative riding. However, this second choice requires premium fuel and is limited to only a couple of models, e.g. G650GS, but may be a better choice for those who prefer the traditional high-revving motorcycle to the flat-torque, limited top end of the first choice.
Of note for those looking to compromise a few MPG for a comfortable smooth sportbike that can do 172 MPH, (from first hand experience) corners with the best of today's streetable liter bikes, holds 5 gallons of, for the most part, 87 octane fuel, it is the 2000 - 2003 California EVAP specification Kawasaki Ninja ZX-9R. It does 48 MPG in stock form and it'll do well over 50 MPG if you can keep it to speeds below triple digits, off the race track.
Do the math on that and you'll see what kind of range the bike is capable of. It's a sportbike. A bike equally at home riding across town, across the state or into the mountains to tilt some horizons. Think of it as a zesty economy bike. One that'll put a smile on your face every time you twist its throttle.
It won't win a Vetter Fuel Economy Challenge of holding four bags of groceries upright or going 180 MPG, but at the speeds it's capable of, if it ever went by one of those wind-tunnel bikes at speed, it might just remove those bags from the other bikes.