Designed by Steve Lang and Nick Lariviere, the Long-Term Quality Index aims to give the average car buyer better insight on long-term reliability when it comes time to purchase a car. By using real-world used automobile data, the buyer is provided with a way to compare different years, makes, and models based on reliability data taken from vehicles that have been traded in. The Long-Term Quality Index focuses on powertrain issues, and the distribution of automobiles by mileage.

You're able to get a better understanding of your potential automobile lifespan by taking a look at these mileage distribution chart. In these mileage charts, the blue curve with the darker background represents the average distribution of cars (across all makes and models in our database). Many models have a similar distribution of automobile, which represents a normal distribution of automobile (most cars are in the middle range of mileage, between 120,000 and 180,000 miles).