As I am not suitable to say much about an engine performance as I ride only 23 km yet but the power of an engine is awesome. You will fill the power when you overtake any vehicle.
As per the yamaha service centre this bike will give you a mileage within 45 to 50 km in city rides like bangalore and on highway. People claims upto 55 km if you drive on eco mode.
Gear box is smooth one down and all are up.