Selecting a petrol or diesel car depends upon your monthly car usage, i.e. the number of kilometers you drive in a month. If you travel more kilometers in a month than go for a diesel car and if your car usage is very less, say less than 1000 kilometers in a month than buy a petrol car. Petrol cars are good for maintenance cost as compared to those diesel ones. Diesel engine cars should be used more rather than keeping them parked in one place for many days, but a petrol car can be kept unused for many days, just u need to take care of your car battery.