It seems like it should be simple for car companies to maintain customer loyalty — if they make good cars, people should keep buying them. Often, drivers find a car they like and, when the time comes to replace it, they stick with the same company.

Yet this is not always the case. Consumers may want to try something new, or they may have had a bad experience with their current car and opt for something completely different. Some companies have found the key to ensuring that most of their customers come back, while others can only retain a fraction of their previous buyers.

To determine the car brands with the most and least loyal customers, 24/7 Wall St. reviewed J.D. Power data on the share of drivers who bought or leased the same brand of vehicle as their previous one over the past year.

While the best carmakers know how to churn out many different models of quality vehicles, others are able to rely on classic autos that have been around for decades. Some cars, like the Chevrolet Corvette or the Ford Mustang, manage to capture the imagination of drivers and the demand for those vehicles never seems to fade. Many of the car brands with the most loyal customers have been able to reinvent their most popular models, ensuring that these vehicles stay on American roads for decades. These are the longest-running car models.

Carmakers must ensure that there are not any glaring flaws in the designs of their vehicles, which can not only endanger lives, but also lead to extensive and costly recalls and damage a brand’s reputation. These high-profile incidents can drive car buyers to look elsewhere when they need a new vehicle. Some fatally flawed cars are still remembered years later as disasters. These are the deadliest cars of all time.

Click here to see the least loyal car brands
Click here to see the most loyal car brands
Click here to read our methodology