Poor engine power

Engine power is not good especially very bad in1.2 petrol engine.sitting with 4 persons it lack much more in power .infact it is not near to 800cc of maruti....so disapointed after purchasing this vehicle...infact same engine in hundai and maruti even in tata is much more powerfull.even mileage is not up to mark .company claims16,18 but still not getting more than12 after 10000 km done.