It is a fact that the fuel average mainly depends on your driving style, if you push your car to the limits, then don't expect a good fuel average, however, if you drive with a light foot and use less sudden braking, any car will give you a great fuel average.
Secondly, the manual transmission usually gives a better fuel average than the automatic ones if driven in a proper way.
Lastly, according to my personal experience, I do have a 2005 Civic VTi Oriel manual transmission, and a 2011 Civic VTi Oriel Prosmatec in the past and the 2005 Civic gave me a better fuel average being the manual transmission, still, the fuel average of the 2011 Civic VTi Oriel Prosmatec is also not that bad (a little difference in both the cars in terms of fuel average).
