{
  "slug": "petrol-car-fire",
  "question": "What are the odds of a petrol car catching fire spontaneously?",
  "category": "transport",
  "no_reliable_estimate": false,
  "perceived": {
    "description": "Vehicle fires barely register in most drivers' risk calculus. The cultural image of a car fire is a post-crash Hollywood fireball, not a parked sedan smouldering from an electrical short. Meanwhile, EV battery fires command disproportionate media coverage relative to their incidence. The result is an inverted perception: many drivers assume electric vehicles are uniquely fire-prone while treating the baseline ICE vehicle fire rate as negligible. Few car owners realize that mechanical and electrical failures in gasoline vehicles cause roughly 190,000 highway fires per year in the US, the vast majority with no collision involved.\n",
    "rough_estimate": "~0.1-0.5% chance over a car's lifetime",
    "kind": "intuition"
  },
  "native": {
    "display": "~69 fires per 100,000 registered vehicles per year (all ages, US)",
    "numerator": 69,
    "denominator": 100000,
    "unit": "fires per registered vehicle per year (all vehicle ages)",
    "population": "US registered highway vehicles, NFPA analysis of NFIRS/FHWA data (2018-2022 avg)"
  },
  "normalized": {
    "lifetime_us_adult": 0.008,
    "display": "~0.8% probability of a fire over a 12-year vehicle ownership span (registration-based, US)",
    "log_value": -2.1,
    "assumptions": "NFPA recorded ~196,000 highway vehicle fires per year (2018-2022 avg) across ~282 million registered vehicles (FHWA), yielding ~69 fires per 100,000 registered vehicles per year, or an annual rate of 0.069%. Over a 12-year ownership span: 1 - (1 - 0.00069)^12 = 0.00825, or ~0.8%. The widely cited AutoInsuranceEZ figure of 1,530 per 100,000 uses annual vehicle SALES as its denominator rather than registrations; since the US has ~282 million registered vehicles but only ~14 million new-car sales per year, the sales-based denominator is ~20x smaller, inflating the rate by the same factor. AutoInsuranceEZ also divides cumulative fire counts across all vehicle ages by a single year's sales, further compounding the mismatch. The NFPA registration-based figure is the methodologically appropriate rate for estimating per-vehicle fire probability. For newer vehicles (2016-2018 model years), the HLDI non-crash fire claim rate was ~10 per 100,000 insured vehicle-years, roughly 7x lower than the all-ages NFPA figure and 150x lower than the AutoInsuranceEZ figure. Vehicle age remains the strongest predictor of fire risk. 95% of vehicle fires are non-collision. ICE vehicles are 18-61x more likely to catch fire than EVs depending on dataset (AutoInsuranceEZ: 61x using sales denominator; Swedish MSB: 18x using registrations). The existing ev-battery-fire entry covers the EV side.\n",
    "uncertainty": {
      "low": 0.001,
      "high": 0.02
    },
    "scope": "activity_specific_lifetime"
  },
  "sources": [
    {
      "url": "https://www.autoinsuranceez.com/gas-vs-electric-car-fires/",
      "title": "Gas vs Electric Car Fires",
      "publisher": "AutoInsuranceEZ (analysis of NHTSA/BLS data)",
      "source_type": "reputable_reference",
      "statistic": "ICE vehicles: 1,529.9 fires per 100,000 vehicles; EVs: 25.1 per 100,000; hybrids: 3,474.5 per 100,000",
      "excerpt": "\"Gas-powered vehicles had a fire rate of 1,529.9 per 100,000 sales. Electric vehicles had the lowest rate at 25.1 per 100,000. Hybrid vehicles had the highest rate at 3,474.5 per 100,000.\"\n",
      "source_date": "2022-01-01",
      "source_accessed": "2026-04-24",
      "archive_url": "http://web.archive.org/web/20260522084131/https://www.autoinsuranceez.com/gas-vs-electric-car-fires/",
      "calculation_notes": "AutoInsuranceEZ used NHTSA recall data, NTSB investigations, and BLS vehicle fire statistics to compute per-100K fire rates by powertrain. Critically, the denominator is annual vehicle SALES, not registrations. The excerpt itself reads \"per 100,000 sales.\" Since the US has ~282 million registered vehicles but only ~14 million new-car sales per year, using sales as denominator inflates the rate by roughly 20x compared to a registration-based calculation. The ICE rate of 1,530/100K-sales includes all vehicle ages and both collision and non-collision fires. The 61:1 ICE-to-EV ratio is the most widely cited comparison but is criticized for both the sales denominator and the age mismatch (the EV fleet is much younger on average). The hybrid rate of 3,475/100K-sales likely reflects the dual powertrain complexity.\n"
    },
    {
      "url": "https://content.nfpa.org/-/media/Project/Storefront/Catalog/Files/Research/NFPA-Research/US-Fire-Problem/osvehiclefires.pdf",
      "title": "Vehicle Fires",
      "publisher": "National Fire Protection Association (NFPA)",
      "source_type": "reputable_reference",
      "statistic": "195,927 highway vehicle fires per year (2018-2022 avg); 579 deaths; mechanical failure (45%) and electrical failure (21%) as leading causes",
      "excerpt": "\"An estimated average of 195,927 highway vehicle fires occurred per year from 2018 to 2022, causing an average of 579 civilian deaths, 1,336 civilian injuries, and $2.2 billion in direct property damage annually. Mechanical failure or malfunction was the leading cause at 45 percent.\"\n",
      "source_date": "2024-11-01",
      "source_accessed": "2026-04-24",
      "archive_url": "http://web.archive.org/web/20241005045502/https://content.nfpa.org/-/media/Project/Storefront/Catalog/Files/Research/NFPA-Research/US-Fire-Problem/osvehiclefires.pdf",
      "calculation_notes": "NFPA's annual vehicle fire report is the authoritative US source. 195,927 fires/year across ~282 million registered vehicles (FHWA) = ~69 fires per 100,000 registered vehicles per year. This is the basis for the native stat. The rate is ~22x lower than AutoInsuranceEZ's 1,530/100K figure primarily because NFPA uses registrations as denominator while AutoInsuranceEZ uses annual sales (~20x smaller). The remaining difference is that NFPA counts fire department responses only. 95% of vehicle fires are non-collision (USFA 2014-2016 data). Wire insulation is the most common first-ignited material (~30%), followed by fuel from engine area (18%).\n"
    },
    {
      "url": "https://www.iihs.org/media/c93b98d8-6a7d-44a1-810e-4468ec539e05/uIu4tg/HLDI%20Research/Fire%20losses/HLDI_FireLosses_1218.pdf",
      "title": "Noncrash Fire Losses",
      "publisher": "Highway Loss Data Institute (HLDI / IIHS)",
      "source_type": "reputable_reference",
      "statistic": "Non-crash fire claim frequency: ~0.1 per 1,000 insured vehicle-years (10 per 100,000) for 2016-2018 model year vehicles",
      "excerpt": "\"Non-crash fire claim frequency for 2016-2018 model year vehicles was approximately 0.1 claims per 1,000 insured vehicle-years.\"\n",
      "source_date": "2020-12-01",
      "source_accessed": "2026-04-24",
      "archive_url": "https://web.archive.org/web/20260426205543/https://www.iihs.org/media/c93b98d8-6a7d-44a1-810e-4468ec539e05/uIu4tg/HLDI%20Research/Fire%20losses/HLDI_FireLosses_1218.pdf",
      "calculation_notes": "HLDI data covers only newer vehicles (2016-2018 MY) and only insurance claims, not all fire department responses. The 10/100K rate for newer vehicles vs the NFPA registration-based 69/100K for all ages demonstrates the extreme age-dependence of vehicle fire risk (~7x difference). The 150x gap versus the AutoInsuranceEZ figure (1,530/100K) is misleading because the latter uses a sales denominator. This is the most useful figure for owners of newer vehicles.\n"
    }
  ],
  "comparison_anchors": [
    {
      "label": "EV battery fire (per vehicle lifetime)",
      "lifetime_us_adult": 0.003
    },
    {
      "label": "Home fire death (lifetime, US)",
      "lifetime_us_adult": 0.0025
    },
    {
      "label": "Death in a car crash (lifetime, US)",
      "lifetime_us_adult": 0.0108
    }
  ],
  "personal_factor_multipliers": [
    {
      "factor": "vehicle less than 5 years old",
      "multiplier": 0.15,
      "notes": "HLDI data shows newer vehicles have ~10 fires per 100,000 vs ~69 for all ages (NFPA/registration-based); vehicle age is the strongest predictor of fire risk"
    },
    {
      "factor": "vehicle over 15 years old with deferred maintenance",
      "multiplier": 3,
      "notes": "Degraded wiring insulation, fuel line deterioration, and worn gaskets dramatically increase fire risk in older vehicles"
    },
    {
      "factor": "aftermarket electrical modifications",
      "multiplier": 2,
      "notes": "Electrical failure/malfunction causes 21% of vehicle fires; poorly installed aftermarket wiring is a common contributor"
    },
    {
      "factor": "hybrid vehicle (dual powertrain)",
      "multiplier": 2.3,
      "notes": "AutoInsuranceEZ data shows hybrids at 3,475/100K -- the highest rate of any powertrain type, likely due to dual-system complexity"
    }
  ],
  "short_label": "Petrol car fire",
  "myth_framing": "underrated",
  "outcome_severity": "serious_harm",
  "exposure_pattern": "recurring",
  "outcome_type": "property",
  "valence": "negative",
  "caveats": "The headline ~0.8% lifetime figure uses NFPA fire counts divided by FHWA registrations (~69/100K/year), the methodologically standard approach. The widely cited AutoInsuranceEZ figure of 1,530/100K uses annual vehicle SALES as denominator — since registrations outnumber sales ~20:1, this inflates the rate by roughly 20x, producing a misleading ~17% lifetime figure. For a new car buyer, the HLDI rate of ~10/100K (2016-2018 model years) is the most relevant — about 7x lower than the all-ages NFPA figure. Vehicle age is the strongest predictor; older vehicles with degraded wiring and fuel lines dominate the statistics. The uncertainty range (0.1%-2%) spans from the newer-vehicle HLDI rate (1 - (1-0.0001)^12 ≈ 0.12%) to roughly 2x the NFPA-based estimate to account for older-than-average fleet segments. The Swedish MSB data (68 vs 3.8/100K) uses registrations and controls better for fleet age, showing ICE vehicles at 18x the EV rate. Most vehicle fires cause property damage only; the fatality rate is ~579 deaths per ~196,000 fires (0.3% of fires are fatal).\n",
  "quality_score": {
    "d1": 3,
    "d2": 5,
    "d3": 5,
    "d4": 4,
    "d5": 5,
    "d6": 4,
    "d7": 5,
    "d8": 5,
    "avg": 4.5,
    "scored_by": "extracted-from-transcript",
    "scored_at": "2026-04-26",
    "methodology_version": "1.0"
  },
  "reviewer": "8d-quality-review-agent",
  "last_reviewed": "2026-04-26",
  "reviewed": true,
  "generated_at": "2026-04-24",
  "image": {
    "alt": "A car engine bay with visible wiring and hoses, flat vector illustration in muted tones."
  },
  "attribution": "Likelier — https://likelier.app",
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
  "support": "https://buymeacoffee.com/kgluszczyk?via=likelier&utm_content=api-fear-single",
  "canonical_url": "https://likelier.app/petrol-car-fire"
}