MileageCurve What breaks, and at what mileage

NHTSA complaint analysis · 318 vehicle generations

Find out what breaks on your car — and when

Complaint databases tell you how many owners had a problem. They almost never tell you at what mileage. This one does.

318 generations · type a model, or a year and a model

Most reported vehicles

Complaints analysed
2,118,076
With an odometer reading
1,108,500
Generations covered
318

Figure 1 · Toyota Prius 2010–2015 · 3,988 reports

Counts tell you a car has a problem. Timing tells you which problem.

Bar spans the middle half of reports; the notch inside each bar is the median. Miles at failure on a proportional scale — equal distances are equal ratios, not equal miles.

  1. Electronic brake control502 reports3,0001,000–5,500Electronic brake control: 502 reports, median 3,000 miles, middle half 1,000 to 5,500 miles.
  2. Hydraulic brake circuit935 reports3,5001,000–7,500Hydraulic brake circuit: 935 reports, median 3,500 miles, middle half 1,000 to 7,500 miles.
  3. Throttle and speed control370 reports5,0001,500–18,000Throttle and speed control: 370 reports, median 5,000 miles, middle half 1,500 to 18,000 miles.
  4. Electrical system425 reports59,00013,000–113,000Electrical system: 425 reports, median 59,000 miles, middle half 13,000 to 113,000 miles.
  5. Brakes1,436 reports87,00034,000–128,000Brakes: 1,436 reports, median 87,000 miles, middle half 34,000 to 128,000 miles.

The hydraulic brake circuit fails at a median of 3,500 miles. The brakes as a whole at 87,000 miles — ordinary service life.

Two different problems, one word in the database, and the middle half of each does not overlap the other. See the full Prius page →

Ordered by median mileage, earliest first. The first 12,000 miles are shaded: that is the boundary this site uses between a manufacturing defect and ordinary wear, not a property of the world.

Source: NHTSA Office of Defects Investigation, public domain.

Figure 2 · Toyota Prius, two generations

Same model name, different mileage curve

Share of each generation’s own mileage-tagged reports filed at or below each mileage, on a linear 0–200,000-mile axis. Shares of reports, not failure rates — and not a ranking.

  • Prius 2004–2009 — 7,289 reports with mileage
  • Prius 2010–2015 — 3,988 reports with mileage

Half of the Prius 2010–2015 reports arrive by 15,000 miles; the Prius 2004–2009 takes 55,000. Same nameplate, different curve — that is what every page here shows.

Source: NHTSA Office of Defects Investigation, public domain.

Browse 318 generations across 28 makes

Built from the NHTSA Office of Defects Investigation dataset, refreshed monthly · how it is built · open data · source