Generally tyres lasts for about 40,000-50,000 km. However this figure is just an estimated figure. Tyre wear depends on number of factors like your driving style, general maintenance like alignment/balancing and checking tyre pressures regularly.
I use a Hyundai Santro Xing (2012 model). The car is mainly driven on highways with not very good road-surfaces. Recently, I noticed the front tyres on my car with uneven tyre wear on one-side. I took the car to the repair shop where I was told to replace the tyres because they are worn out due to improper wheel alignment. I wanted to know if it is really necessary to replace the tyres?
A car that is being driven with misaligned wheels tends to ‘eat’ the rubber and causes uneven tyre wear. Driving a tyre with an uneven wear pattern will greatly reduce steering response- the car will tend to ‘pull away’ which will eventually be of great concern to you as a driver. It is advised that you replace the tyres asap (stick with the same tyre size and rating as before); get the wheel-alignment done and also have front suspension components such as tie rods and ball joints etc., checked