Add dataset card

README.md

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+---
+license: cc-by-4.0
+language:
+- en
+pretty_name: "Engine-Family Complaint Density (NHTSA, MY 2005-2025)"
+tags:
+- automotive
+- engines
+- nhtsa
+- vehicle-reliability
+- engine-defects
+- recalls
+- open-data
+- consumer-data
+size_categories:
+- n<1K
+configs:
+- config_name: default
+  data_files:
+  - split: train
+    path: engine-complaint-density.csv
+---
+
+# Engine-Family Complaint Density
+
+Curated problematic engine families (documented defect patterns — class actions, NHTSA investigations, or 100+ fleet complaints), with total NHTSA complaints, recalls, and complaints normalized per model-year entry. Density lets you compare families of different production volumes.
+
+## Columns
+| column | meaning |
+|---|---|
+| `engine_family` | Engine family name |
+| `manufacturer` | Manufacturer |
+| `displacement` | Displacement |
+| `configuration` | Engine configuration |
+| `years` | Production years |
+| `modelyear_entries` | Matching model-year entries in DB |
+| `complaints` | Total NHTSA complaints across the family |
+| `complaints_per_modelyear` | Complaints ÷ model-year entries |
+| `recalls` | Total recalls across the family |
+| `alleged_fires` | Complaints alleging fire (unverified) |
+| `alleged_deaths` | Complaints alleging death (unverified) |
+| `url` | Source page on ProblemsByVin |
+
+## Source & methodology
+Families are the editorial set powering /engines/. For each family we sum complaints/recalls/harm flags across every matching (year, make, model) in the DB. "complaints_per_modelyear" = total complaints ÷ model-year entries present. Complaints are unverified consumer reports.
+
+Canonical version, full methodology, and the other datasets: **https://problemsbyvin.com/data/** .
+
+## License
+CC BY 4.0 — free to use with attribution to **ProblemsByVin (https://problemsbyvin.com)**.