About Diagsheet

When an owner files a safety complaint with the National Highway Traffic Safety Administration, it lands in a public file: the car, the part involved, the mileage if the owner gave one, and what happened in their own words. Manufacturers file their recalls with NHTSA too. The agency's own defect investigations go into a third file. Diagsheet reads all of them every day and lays them out one vehicle at a time.

Why mileage comes first

A list of everything that ever went wrong with a model isn't much use to someone standing next to one particular car with 84,000 miles on it. That person wants to know which problems are already behind them and which tend to show up later. So each vehicle page asks for your mileage and sorts the problems around it, splitting the ones owners usually hit before your reading from the ones still ahead. (Mileage only counts when the owner gave one, so the track is drawn from the reports that did.)

What's on the site today

As of Oct 2, 2026 the site covers 1,045 model years of 246 models from 35 makes. That's built from 350,340 owner complaints received by NHTSA between Jan 1, 2015 and Sep 29, 2026, along with 2,240 recall campaigns and 229 NHTSA investigations that touch those vehicles.

Each vehicle gets a page with its problems laid out by mileage. Every problem that has at least 25 reports on that vehicle gets its own symptom sheet, where you can tick the phrases that match your car and see how many owners described the same thing. Model years with at least one recall have a recall page listing each campaign with the complaints filed on the same system. A model page compares every year of that model by complaints for each year on the road, which is where the "years to avoid" calls come from. Model years from 2025 on get a month-by-month log instead, since there isn't enough mileage on them yet for a track to mean anything.

What it won't do

Diagsheet doesn't diagnose your car or tell you whether it's safe to drive, and it won't guess at a repair bill. It tells you what owners of the same car reported and at what mileage, what they say got replaced and sometimes what they paid, and whether the manufacturer or NHTSA has done anything about it.

Bring that to a mechanic. Don't use it instead of one.

The counts need care, too. A complaint count isn't a failure rate, and popular models collect more complaints simply because more of them are on the road. What the counts can't tell you goes through the traps one at a time.

Independence

Nobody in the car business pays for placement on Diagsheet or supplies its data. The site is paid for by ordinary display advertising from Google. Google's systems choose which ads appear, and no advertiser has any say in what a page reports. The privacy page covers what those ads collect and how to opt out.

When something's wrong

If a number, a grouping or a label looks wrong, the editorial policy explains how corrections work and lists the ones made so far. The words in an owner's complaint belong to NHTSA's record, so a change to one has to go through NHTSA; the contact page says how. Terms like "remedy" or "engineering analysis" are explained in the glossary.