Gas Vs Electric Accident and Fire Safety

There have been about 250 million cars in the US in most years from 2010 to 2022. The level has slowly increased to 280 million.

The insurance site Auto Insurance EZ compiled sales and accident data from the Bureau of Transportation Statistics and the National Transportation Safety Board. The site found that hybrid vehicles had the most fires per 100,000 sales at 3474.5. There were 1529.9 fires per 100k for gas vehicles and just 25.1 fires per 100k sales for electric vehicles.

Let us sanity-check the numbers. Average cars last for about 12 years. There are about 6 million car accidents in an average year in the USA. There are about 180,000-220,000 car accidents that involve a fire each year. 3% of the car accidents have a fire. This would suggest that 2.4-3.0 million car fire accidents for the 12-year-life of 250 million car cohort (2008-2020). This would be 0.9-1.2% of gasoline or diesel cars will have a fire accident over the life of the vehicle. There would be 72 million car accidents of any kind over the 12-year-life of 250 million car cohort. Around 29% of the cars get into some kind of car accident. The actual total would be less at around 20-25% as some cars would be in multiple accidents.

Only about 5 percent of car fires result from a collision. But those account for 6 in 10 of all fatal vehicle fires. Less than 2 percent start in the fuel tank or lines. Most of these fires begin with problems in the engine, drivetrain or wheel areas. They may also be caused by a faulty design or defective parts. There are more than 19 vehicle fires every hour in the United States. They account for 1 in every 8 calls that fire departments respond to.

More than a third are the result of some unintentional action, either careless behavior or accidents. And nearly a quarter are caused by equipment failure or a heat source in the car or truck.

However, there are some claims that most vehicle fires are caused by a crash. What causes a car to catch fire in an accident? Most fires originate within the vehicle, such as a broken fuel line coming into contact with an overheated engine.

Heat from powered equipment, the engine or drivetrain, and sparks from friction or electrical arcs account for 2 in 3 vehicle fires. Smoking or some other type of open flame accounts for 7 percent of fires.

There are about 6 million hybrid vehicles on the road now in the US. However, the average number for 2008-2020 would be about 3 million hybrid vehicles. This is a little over 1% of the total vehicles. The usage pattern of the hybrid cars should be the same as the gas cars. They are driven just as much and at similar speed on highways. The Auto Insurance EZ statistics suggest hybrid cars are twice as likely to have an accident become an accident with fire.

There are about 2 million battery electric cars in the USA now. However, the vast majority were sold in the last three years. The early cars in the 2008-2013 timeframe were very few and most of them had terrible range. The usage pattern would be different. They would primarily be commuter cars (a short drive to some stores or a short drive to and from work.) From 2017 to 2022, 70% of the cars would be Tesla cars. They would have longer range and more usage. Tesla’s have better safety statistics. They do not get into as many accidents and if they do get in an accident the driver and passengers are safer. Electric cars are virtually impossible to roll. The heavy batteries are on the bottom of the vehicle.

We would need to match the electric cars statistics to the 12-year average life and miles driven for the gas cars. We need to boost the Auto Insurance EZ compiled statistics for electric car accident fires by at least 4 to 6 times to match the 12-year life of the gas cars. There may need to be a double or triple to align the usage patterns. Tesla company statistics report that the cars get into fewer accidents. Tesla cars get into accidents once in every 4 million miles vs once in every 500,000 miles. The electric cars statistic of being 60X less likely to have a vehicle fire could be explained by not having the full time for accidents to occur (2-3 years and not 12 years, 4-6X) and the usage pattern difference and some superior safety accident avoidance systems in Teslas (8X). However, the statistic that most of the car fires are not the result of car collisions complicates the analysis.

Electric cars seem to be safer but there need to be more cars in a study and a matching 12 year period of comparison. If the usage pattern of electric cars changes then this is important to the changing safety profile. Electric trucks, Semi and SUVS are just now appearing. Electric trucks, taxi and buses have higher usage rates and different usage patterns.

13 thoughts on “Gas Vs Electric Accident and Fire Safety”

  1. You write that the average car lives 12 years in the US but I read:
    “Automobiles in the United States had an average age of 12.1 years in 2021. This figure represents a slight increase from 11.9 years in 2020.”
    To me that means the average age of cars in the US is 12.1 years. Am I reading that wrongly?
    Older cars are of course more prone to all sorts of mishaps. But the average age of EVs is much lower than 12 years. So there is a considerable age derived bias in favour of EVs in your assertion.

  2. Should be noted some battery packs are now fire resistant, but those batteries have even worse range, and would not have an exact usage pattern compared to longe range bev or hybrid/gas cars. I doubt there will ever be an apples to apples comparison, but I’d lean on the side of bev vehicles having lowest fire risk in due time, even if only for the lighter usage, with increased fire resistance being a welcome bonus.

  3. I appreciate the ‘real’ world statistics, but the type of drivers, their habits, car quality, and maintenance routines (adherence to such) are very different with gas car users, hybrid-type buyers, and the early adopter-type in BEVs and high-end xEVs. As an analogy: my expensive toll road highway (65 mph+ separated) nearby has an accident rate of less than 5% as compared to the nearby public highway (65 mph+ separated) with almost comparable rush hour volumes (except way fewer trucks). Why? Better cars. Better drivers. (also better road maintenance).
    The point is that it is better to compare ‘failure methodologies’ of the vehicles under controlled conditions (which is hugely available). You want to see ‘what it takes to fail’. This is similar to testing Building materials in fire chambers. My issue is more about how survivable and controllable/ extinguishable a fire is when it has already started – witness the over-the-top regulations against propane cars in public garages and other confined spaces.

    • Can’t imagine larger Li-type and similar battery systems being restricted in public confined spaces as with the wide ranging regulations on carrying too many batteries in an airline cabin. A few European cities had placed bans on EV charging (though storage-only restriction is less clear) in certain confined garages. The risk is way above negligible.

      • This is very real. The failure of steel structure under extended periods of very high temperatures is widely documented; note the requirements for some type of fire resistance encapsulating the steel in buildings. Typical concrete structural properties also decline under long periods of raised temperatures. Not heard much on hydrogen-based propulsion systems EV or ICE with fire risks.

      • European cities amirite?
        Could be demand destruction that stagnates EV sales, not for want of vehicles. Shame if the lost ‘economis of sale’ in EV production doom us all to unnecessary higher prices per:
        NEWS: Paris and other major EU centres will be banning most car traffic in a year

  4. ” Less than 2 percent start in the fuel tank or lines.” “Most fires originate within the vehicle, such as a broken fuel line coming into contact with an overheated engine.”

    This is a common misunderstanding of what goes on in a car fire. Car fires are normally initiated by a large OIL leak, not a fuel leak. (Diesel cars can be an exception here.) Ignition of fuel typically happens after the oil starts the fire, if it happens at all. (Remember, the fuel is usually stored at the opposite end of the vehicle from the engine, on purpose.)

    The ignition temperature of gasoline is way above its boiling point; (535F vs 158F for summer gas.) If you leak gasoline onto a hot surface, the exhaust manifold, say, evaporation keeps it from igniting unless an ignition source (Open flame, sparks.) is already present.

    By contrast, the ignition temperature of oil is roughly the same as its boiling point: Oil spilled on a hot surface will ignite before it boils away.

    So almost all “car-B-q’s” start as oil fires, not fuel fires. And most of them stay that way.

  5. I wonder what happens “IF” there are a multitude of electric truck fires?
    Is it the usage pattern, the charging system, the simple magnitude of batteries?

    Will be interesting to watch the data get compiled

  6. I’ve heard EV battery fires are something horrendous to douse. Like it takes hours and sometimes days to put them out. Anyone heard the same?

    • I heard hours.
      It’s not really a fire, it’s a short circuit. The water will cool it, but denying oxygen does not stop it.

      • I once destroyed (intentionally) an old phone battery. To me it looked like a metal fire. I also put water on it, which made it, as I expected, worse.

  7. We would need to compare fire rate by age. If 1 year old gasoline cars still have 10x the rate of electric cars we know the game is up.

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