BRV poor milage and poor pickup , poor engine performance

I have purchsed new BR V VX Petrol top model. Car is family car but main disadvantage which is very risky also that poor performance of engine. I have drive about 1700km. With four family members and three bags of 35 kg weigt on pune kolhapur express highway. It was ver bad experince that BRV is having poor perfotmance with Ac . It does not take pickup after sudden breaking. Also average milage with ac on express highway with speed 80-85km which is now a days very essential on such good road express highway , milage is 13.2km. However company claims 15.4km. Thoes who want to drive such car with 90 and above speed and expecting good milage with good pickup then BRV is not suitable.