How we collect and count data

We use public data from the U.S. National Highway Traffic Safety Administration (NHTSA): official recall campaigns and complaints filed by vehicle owners.

Complaints are grouped by vehicle year, make and model, then by the component involved (for example, engine or electrical). We count each complaint once.

Fixes are ranked from easiest to hardest based on typical cost, tools and skill needed. Rankings are general guidance only.

Complaint counts are owner reports and are not verified by NHTSA. A high count does not prove a defect.