Hi Saurendra, You can go for Maruti Alto and it has a godd performance and less maintenance and value for money, Hyundai Santro Xing as good performance but high maintenance than the Maruti, Chevrolet Spark more costly than these two vehicles and small car than the Maruti Alto and Hyundai Santro Xing. Compare Maruti Alto, Hyundai Santro Xing and Chevrolet Spark for more details please click on the following links. Thank You
To get the best mileage from your vehicle, we will advise you to get your car serviced on time, regular check for tyre pressure and follow speed limits. Please visit link this link for more such tips- http://www.cardekho.com/advisory-stories/driving/tips-to-ensure-good-fuel-economy.htm
ECU (Engine Control Unit) is a electronic control unit, which control engine operations ensuring optimum running. If the ECU of your car has been damaged, please visit authorized Tata workshop to know the cost of the ECU and to get it replaced.