If this would have not been driven by me. I also might have been hesitant to acknowledge this. yes you are right My auto 1.8 altis is also
giving me around 13-14 km/l. (autos show inclination for more fuel intake) . BTW r u using stock size tyres in ur car. ?
But the difference lies in Air filter quality and manual trans and tire size , e.g if stock size is 185/65/14 and opt for 195/65/15.. (which many people go for) per simple mechanics the car will have less torque as this will appear as excessive load for engine, and to compensate ECU will increase fuel in take.