Maruti Suzuki Wagon R Vxi - very very poor mileage. Review on Maruti Suzuki Wagon R

I drive a Maruti Suzuki Wagon R Vxi bought during Aug 2011. I find a mileage of 13.6 km/ltr of petrol with A/C on at times at level 1 only and driving 60% in expressway and 40% in city. I am shocked to the extent that I thought I am taking wrong measurement. After repeated checks I found out it's only 13.6 km/ltr to 13.5km/ltr. Then I checked the manual, it says first 360 km you cannot have too much of pressure on gear or breaks - mentioned under section running. They advertise for 18.5 to 19 km/ltr. Even with a/c(that is 10% less) and expressway/city driving ratio, I expect to get at least 16 km/ltr, I am getting way less. This is not expected of maruti where they claim they quote less and customers get more than what they say. It's a big jolt to there reputation although I am there customer for last 9 years. There's a blind spot between right of driver and left of right mirror. This is not the case with esteem. Engine power is less(meaning not efficient), pickup is very less. With sudden break there's a drag which may lead to accident that's because of tall boy structure