I Resolved my issue. actually the problem was very simple. first the air filter was very dirty i removed it and clean it with blower. second it was also fault of my own driving habit which was changed for couples of weeks now after i changed my habit it also contributed to increase my overall fuel average. I was press gas pedal too much hard in small gears like if i was in first gear i was moving 30 kmh and then changed to second. second to third the speed was almost 45 to 55 and so on. so for this reason my RPM going 3000 to 3500. now I changed my driving style and habit. mostly now i drive in 5th gear even my speed is between 45 or 50 . RPM remains in between 1000 to 2000 above will consume alot of fuel (of course speed I get on this limited RPM is not higher than 70KMH but in city it is acceptable. but for long drive I have not tested yet). another thing I learn that I I should not changed my gear rapidly. i changed my gear only when i came a feel that if i do not lower the gear my car will start vibrate so before this thing happen i changed my gear to lower. i also changed break patterns and other small things. it helps a lot and today i got 16 km average in city with ac that was awesome on 2010 Cultus. thanks
