I haven't heard of any ICE engines spontaneously combusting. I have heard of many lithium batteries, primarily in phones, combusting. We're better at keeping gasoline safe than charged electrical energy.
- 47% mechanical
- 21% electrical
- 7% intentional
- 6% exposure
- 4% crash, overturn, run-over
- 2% smoking
So crashes are a relatively rare cause. They also break it down by the area the fire started:
- 63% engine area, running gear, or wheel area
- 11% passenger/operator area
- 5% cargo/trunk
- 3% exterior
- 2% fuel tank or line
Interpolating between those numbers, you might guess that between 20% and 40% of fires could be described as "engine spontaneously combusting." That would be 45,000 - 90,000 per year in the US.
So despite you never having heard of it, it does happen.
[0] https://www.nfpa.org/vehiclefires, numbers above from report table 8 & 9
Most interesting is that the first part of an ICE to catch on fire is most frequently the electrical wiring. And even if it is a flammable liquid (the second most likely cause), it's only a 42% chance that liquid was gasoline!
Thanks again, it's interesting reading.
He noticed significant tingling in his feet while pushing the car out. This was in the days before GFCIs. He's lucky he wasn't electrocuted.
It'd been parked for an hour or two, and the trigger was something electrical in the engine cavity.
https://www.caranddriver.com/news/a35782883/kia-cadenza-spor...
https://www.autosafety.org/ford-ignition-switch-fires/
https://www.mlive.com/news/2021/03/2021-ram-truck-owner-enco...
https://www.industryweek.com/operations/safety/article/21963...
https://www.auto123.com/en/news/gm-recall-risk-of-fire/61360...
ICE vehicles can have strange failure modes leaking flammable fluids places where they should go where its really hot. Sometimes this gets mixed with a spark from a bad electrical connector, sometimes it drips on something hot.