I have purchased  Hero Honda hunk and it is 5 years old.
If we ride this at 40 kmph u will surely get mileage above 55 and its silky smooth at that speed just make sure you have right air pressure in our tires.
But the major problem thats troubling me is its vibration.
I had made several maintenance upgrades but there is no reduce in vibration.
The Bike is good in mileage and once it gave me a mileage up to 67 kmpl. *