Ones you have decided to purchase a used car, you need to check the history of the car. Here i am going to explain few of the factors that you need to consider before you purchase a used car. 1. Check for how much the distance the car traveled upto date.A petrol car should have a average distance of about 12000 Km/year. But a diesel car should have a average distance of about 15000 Km/year. 2. Check for the Age of car. If you are going to purchase a used car check for the age. It should not have crossed more than 3 years. If the car age is more than 3 years, then just leave it. 3. Should be owned by a single owner. If multiple owners have maintained the car, just check for performance and mileage. 4. Check for papers and certificates.