What about petrol cars? Can they not explode? — unenlightened
There is a big difference between "exploding" and "catching fire".
This is a long post. If you don't want to see the details of how the calculations were done then you can skip the details and go straight to the "
Summary of results"
There are at least 5 calculations for the relative risk of gasoline cars catching fire compared to EVs.
1) The EV FireSafe report which was funded by Australia’s Department of Defense. It found that the risk of a gasoline car catching fire was about 83 times bigger than the risk of an EV catching fire. (83 is calculated by dividing 0.1 by 0.0012)
2) A graphic that has been widely shared on the internet which is attributed to the NTSB (National Transportation Safety Board). This graphic hasn't changed since 2018 so we should be careful when using these numbers). It shows that the risk of an EV catching fire is 25.1 per 100k Sales. It also shows that the risk of a gasoline car catching fire is 1,529.9 per 100k Sales. Using these numbers makes the risk of a gasoline car catching fire about 61 times bigger than the risk of an EV catching fire. (61 is calculated by dividing 1,529.9 by 25.1)
3) The Authority for Social Protection and Preparedness in Sweden recently released the first report of its kind specifically tracking EV fires in Sweden and comparing them to combustion-powered vehicle fires, and the results are clear: EVs are much less likely to catch fire.
According to MSB data, there are nearly 611,000 EVs and hybrids in Sweden as of 2022. With an average of 16 EV and hybrid fires per year, there's a 1 in 38,000 chance of fire. There are a total of roughly 4.4 million gas- and diesel-powered passenger vehicles in Sweden, with an average of 3,384 fires per year, for a 1 in 1,300 chance of fire. That means gas- and diesel-powered passenger vehicles are 29 times more likely to catch fire than EVs and hybrids.
4) From
https://www.nautinst.org/resources-page/recognising-the-risk-of-evs.html
Statistically, the estimated failure rate (and therefore risk of combustion) of an individual battery cell is one in ten million. However, when you consider that an average EV contains approximately 7000 cells, the risk increases significantly.
Data from the London Fire Brigade suggests an incident rate of 0.04% for ICE car fires, but the rate for EVs is more than double that at 0.1%. Although it is not clear whether EVs are more likely than ICE vehicles to catch fire, it is common ground that the consequences are potentially more disastrous and more difficult to handle.
Using these numbers makes the risk of a gasoline car catching fire about 0.4 (about a half) times the risk of an EV catching fire. (0.5 is calculated by dividing 0.04 by 0.1)
5) Various statements from Elon Musk
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https://www.theguardian.com/business/2023/nov/20/do-electric-cars-pose-a-greater-fire-risk-than-petrol-or-diesel-vehicles
Elon Musk’s Tesla is the world’s biggest maker of electric cars. It says the number of fires on US roads involving Teslas from 2012 to 2021 was 11 times lower per mile than the figure for all cars, the vast majority of which have petrol or diesel engines. So the risk of a gasoline car catching fire is about
11 times the risk of a Tesla (EV) catching fire
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https://www.greencarreports.com/news/1133254_fires-are-less-frequent-in-teslas-and-other-evs-vs-gas-vehicles
The electric car maker notes, as CEO Elon Musk has for years, that the frequency of EV fire headlines can be deceiving. There were almost 190,000 vehicle fires in the U.S. in 2019, and they happen in gasoline vehicles at a much higher rate. It notes that from 2012 to 2020 there was about one Tesla vehicle fire per 205 million miles traveled—versus one per 19 million miles traveled for all types, citing data from the National Fire Protection Association (NFPA) and U.S. Department of Transportation.
Using these numbers makes the risk of a gasoline car catching fire about 11 times the risk of a Tesla (EV) catching fire. (11 is calculated by dividing 205 by 19)
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https://www.tesla.com/VehicleSafetyReport
Vehicle Fire Data
Our global data indicates that, between 2012 and 2022, approximately one Tesla vehicle fire event occurred for every 130 million vehicle miles traveled. By comparison, data from the NFPA and U.S. Department of Transportation indicate that one vehicle fire occurs in the United States for every 18 million miles traveled.
Using these numbers makes the risk of a gasoline car catching fire about 7 times the risk of a Tesla (EV) catching fire. (7 is calculated by dividing 130 by 18)
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https://www.usatoday.com/story/money/cars/2013/10/04/elon-musk-tesla-fire/2924423
Elon Musk defends Tesla electric car after fire (This is from 2013)
Elon Musk says in comparison to 150,000 vehicles fires a year, Tesla has now had only one out of 100 million miles driven. "This means you are 5 times more likely to experience a fire in a conventional gasoline car than a Tesla!"
Summary of results
The different calculations for the relative risk of gasoline cars catching fire compared to EVs are:
- 83 times more likely
- 61 times more likely
- 29 times more likely
- 0.4 times more likely
The different claims from Elon Musk for the relative risk of gasoline cars catching fire compared to EVs are:
- 11 times more likely
- 11 times more likely
- 7 times more likely
- 5 times more likely (a claim made in 2013)
The large range of values for the relative risk of gasoline cars catching fire compared to EVs is probably due to a number of reasons. The lack of data, and the reliability of the data that does exist, makes all of these values questionable.
An important factor has been left out of these statistical calculations
None of these calculations take into account the age distributions of gasoline cars and EVs on the road. The age distributions of gasoline cars and EVs are very different. There are many gasoline cars on the road which are well over 20 years old. The first mass-market EV, the Nissan Leaf, wasn't released until 2010. Only the earliest modern EVs, of which very few were sold, are over 10 years old today.
An analysis of car fires shows that older cars are far and away the most likely to catch fire and the risk of fire increases the older a car gets. A total of 77 percent of all car fires that occurred in 2017 involved vehicles made in 2007 or earlier, so those at least 10 years old or older. The original Tesla Roadster didn't come out until 2008, and only 2,500 of those were built. The first mass-market EV, the Nissan Leaf, wasn't released until 2010. Only the earliest modern EVs, of which very few were sold, are over 10 years old today. The NFPA report cites worn-out parts and deferred maintenance as the likely cause of increased fire danger for older cars.
How many 20 year old cars are still on the road?
- about 23% of all passenger cars on the road today are 20 years old or older. (none of these are EVs)
Percentage of cars still on the road (some numbers rounded)
Year Range % of Vehicles
2020-24 model years 12%
2015-19 model years 26%
2010-14 model years 19%
2005-09 model years 20%
2000-04 model years 14%
1995-99 model years 5%
1990-94 model years 2%
1985-89 model years 1%
Older than 1985 1%
The average age of electric vehicles (EVs) in the United States is 3.5 years.
The average age of all vehicles in the United States is 12.6 years.
All of the current calculations for the relative risk of gasoline cars catching fire compared to EVs are
NOT comparing apples with apples.
It may be that once the age distribution of gasoline cars and EVs is taken into account that they both have a similar risk of catching fire, There is also the possibility that the risk of an EV catching fire is greater than the risk of a gasoline car catching fire.