are u driving very short distances when u r getting 13/14 avg?
involving lots of speed breaks and stop and go?
r u shifting alot ot just letting it stay in small gears and high RPMs?
what is ur speed when u get 15 KM/l?
to get best out of it, u need to shift to top gear as early as possible and keep the RPM low.
the air pressure in tyre shud be 34/35 as recommended.
Do check the quality of fuel u r getting.
this little car can return u uptp 19 easily if u drive gently.