I am owning both petrol and diesel cars.It is not matter which car you are travelling but the place you are going to reach.Diesel cars are rough and tough but slightly economy.But the maintenance cost is more comparing to a petrol car.To compensate the cost diesel cars should be used at least 60kms.per day.At the same time you have to update your vehicle when you go for a long distance.Fit both Air conditioner and music system in your diesel cars.
On the other hand petrol cars are expensive only when you are filling fuel.Otherwise maintenance cost is negligible and comfort is more.So when you are in city ride my preference will be Petrol car and for long distance use diesel cars.