Methodology

Data sources

Every figure on this site comes from public records published by the National Highway Traffic Safety Administration (NHTSA), part of the U.S. Department of Transportation:

• NHTSA owner complaints: safety complaints filed by vehicle owners
• NHTSA safety recalls: recall campaigns filed by manufacturers
• NHTSA defect investigations: investigations opened by NHTSA's Office of Defects Investigation
• NHTSA 5-Star Safety Ratings: government crash-test ratings
• NHTSA Product Information Catalog (vPIC): used by our VIN decoder

We check these sources regularly, and each page shows the date of the data it was built from.

How to read the numbers

• Each complaint is counted once per vehicle. A complaint that mentions several problems (for example engine and transmission) is counted in each of those problem areas, so area totals can add up to more than the overall total.
• We group NHTSA's technical component names into plain-English problem areas such as Engine, Brakes or Electrical. The original NHTSA component names appear in the “Most-reported components” tables.
• “Worst years” rankings use a severity-weighted score that gives extra weight to complaints involving crashes, fires, injuries or deaths. It is our own editorial measure, not an official NHTSA rating.

Important limitations

• Complaints are unverified. They are reports from owners. NHTSA does not confirm them, and a complaint does not prove a defect.
• No sales adjustment. Best-selling models naturally collect more complaints. Compare model years of the same model, or similar vehicles.
• Age matters. New model years have had less time to collect complaints.
• Privacy. Complaint excerpts are cleaned of personal details such as names, phone numbers, email addresses and VINs.

Some pages include a short AI-assisted summary of what owners report. See our editorial & AI policy.