With two more Bolt fires just 1 day apart, Two on the same day, and one a few weeks later, just how likely is the Bolt to catch fire than a similar gas vehicle? We keep hearing people say that gas vehicles still catch fire far more often, but is that true?
In 2018 there were an estimated 279 million vehicles in the US, 35% of which are cars. That means there are about 98 million cars. Between 2013 to 2017 there were an average of 117,400 car fires per year in the US (i.e. excluding large trucks and busses). That’s about 120 fires per 100,000 vehicles.
With the 2017-2019 Bolt at 15 fires with 68,000 vehicles, that’s only 22 per 100,000. So that’s way better than a gas car, right?
Probably not. The devil is in the details.
The problem is that we aren’t taking into consideration the age of the vehicle, or what was happening at the time. Also, the Bolts are still catching fire. Older gas vehicles are far more likely to catch fire than new gas vehicles (I don’t think there’s enough data to determine for electric, but I suspect it’s opposite). Gas vehicles are more likely to catch fire when they are running than parked and off. So we need to consider not only the age of the vehicle, but also what it’s doing at the time.
The situation that we are concerned with is the Bolt catching fire while parked in our driveway. So let’s dig into the car fires and find out the details to compare to that.
Of all fires, it’s reported that 37% occurred on “residential street, road or driveway” and “vehicle parking area”. That’s not enough to definitively state “parked”, as there will be more captured there than when just parked (they could be driving). There are probably also parked fires not accounted in that, but let’s use that number as a ballpark. That means 43,400 fires per year while “parked”.
Of those, 68% are due to mechanical or electrical failure (the rest have causes unrelated to the car), or 29,500. Of those, only 5% are vehicles less than 3 years old, so ~1,500 total. There are about 17 million vehicles sold per year (2017-2019), so that means 51 million vehicles 3 years of age or newer.
So 1,500 fires out of 51,000,000 cars is ~3 per 100,000 cars. In other words, at 22 per 100,000, overall the Bolt is already roughly seven times as likely to catch fire while parked in your driveway than a similarly aged gas car.
But it gets even worse – at least for the 2019 model year.
Looking at the fires, in 2020 there were five fires of the 2019 Bolt in a little more than 4 months. At least five more have occurred in 2021. According to GM, only 14,371 2019 Bolts were made with batteries manufactured in Korea, and one US produced batteries have caught fire.
Looking specifically at the 2019 Bolt with a Korean produced battery, that’s 70 fires per 100,000 that occurred over 13 months.
But only about 2.5% of all car fires are a less than two years old – so that’s around 2.2 per 100,000. That makes this model a whopping (roughly) THIRTY FIVE times as likely to catch fire than a 2019 gas car. It is worth noting that with these small numbers, the confidence interval will be large, so it’s hard to get an accurate number. Having said that, it’s fair to say that it is at least an order of magnitude more – and that is extremely worrying.
Note that we believe none of the Bolts that caught fire were previously damaged. GM did investigate, and some fires due to damage were not included in the 8 confirmed battery related fires. We don’t know if any of the gas cars had any previous damage, but surely some did, which would lower their incidence rate.