its Prosmatec..i've been there, engine of re-born 2006 to 2009 is not tuned up like the engine of re-born 2010 onwards, whatever you do it will still give you an average of 7 to 8km/l.
only re-born after 2010 gives u an average of 12 to 13 and thats vti-manual not prosmatec.
to improve car's average maybe you can check the following things
1. Air pressure in all tires should be really really balanced.
2. Air filter should be really clean (if possible clean it every week)
3. Car's alignment should be perfect.
4. tires should be perfectly balanced.
5. try to drive in the highest gear possible.
6. (tricky one)... if you plan to overtake any car, make decision just 1 time, as when you are about to overtake the car will shift 1 gear down and then if u fall back it will shift 1 gear up again and when u finally overtake it will again shift 1 gear down...so avoid this gear shifting again and again and try to overtake in one go.
7. if you are driving too slow in a rush hour, shift it to D2, so that you wont toggle between 1st and 2nd gear.
i hope this helps...