Engine-Family Complaint Density — NHTSA Owner Complaints, MY 2005–2025

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. Contents: 21 engine families. Method: 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. NHTSA complaints are unverified consumer reports. Source: U.S. NHTSA owner complaints and recalls (public record), model years 2005–2025. Canonical version and full methodology: https://problemsbyvin.com/data/ . Released under CC BY 4.0 — attribution to ProblemsByVin (https://problemsbyvin.com).