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Comment by ggreer

2 hours ago

I'm not sure, but diesel fires are definitely more of a risk to people. Fuel can quickly spread and ignite before people in the vehicle (or bystanders) have a chance to escape. Lithium battery fires are more contained because individual cells spew flame, which heats up nearby cells, which then undergo thermal runaway. This means that battery fires take longer to release their energy, which is annoying for extinguishing them, but good for anyone who needs to get out of the wreck.

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ggreer

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leonidasrup  1 hour ago

There is a big difference between diesel powered engines and petrol powered engines. Diesel is much harder to ignite and this was for example big advantage for diesel powered tanks during World War II, in comparison to gasoline powered tanks.

"They introduced many innovations as they built their designs, including bell crank suspensions, as pioneers in amphibious tanks, and the use of diesel engines that were less likely to catch fire compared with gasoline tank engines that were being used at the time."

https://en.wikipedia.org/wiki/Tanks_in_World_War_II

The answer from an actual firefighter:

" Diesel has a much higher flashpoint. This means the speed of deflagration is much slower. It cannot convert the diesel to vapour as quickly so can't disperse the fuel as quick to spread the surface area.. "

" Leaking petrol is much more dangerous in an accident. It is far easier to ignite. If any leaking petrol contacts the exhaust or brake discs it could ignite causing rapid flame spread trapping people in the car. Diesel won't do this. "

https://www.quora.com/Is-it-possible-for-diesel-cars-to-expl...

jacquesm  1 hour ago

> I'm not sure

> definitely

If you're not sure, why the definitely?

Lithium packs can light up (much) faster than you sketch here. The process you describe is correct in sequence but it takes about as long to read that sentence to get to a car that is engulfed in flame. More than one person died from the combination of toxic gases and heat before they managed to get out of the car.

Lithium Ion is a very bad battery type for anything that should be safe or moves, LFP is far better and LTO is better still.

  • ggreer  1 hour ago

    The "I'm not sure" referred to road damage. The "definitely" referred to risk to people.

    The fact that some people have died in lithium battery fires doesn't tell you if they're a greater risk than petroleum vehicle fires. Around 500 Americans die in vehicle fires every year. Last year, EVs were around 3% of vehicle miles traveled in the US, so if they're as dangerous as petroleum vehicles, we should expect 15 battery fire deaths in 2025. The actual number seems to be 2 or 3.

  • flanz_10  1 hour ago

    > If you're not sure, why the definitely?

    They said "I'm not sure" to the road surface question, and "definitely more of a risk to people".

    Roads and people are different things.