Driving through dry leaf piles - fire danger?

[MBCook]

It’s that time of year around me when you see lots of piles of dry leaves in the street that just fell off the trees. I was always told never to drive through them in a normal car because the heat of the exhaust, especially the catalytic converter, would catch them and you could cause a fire that may include your car in the destruction.

Then I got to thinking… I’ve never heard anyone say whether it’s still a problem for EV‘s. The battery doesn’t get up to terrible temperatures. The brakes certainly can. I assume the motors get quite toasty.

I don’t intend to try it out, but it anywhere near as dangerous?

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[Flint302]

Kinda, for the neighborhood kid hiding in the leaves.

 

[tbrumleve]

I was always told to avoid leaf piles since you don’t know what’s hiding under them.

Generally, it’s not getting hot enough under the car to combust anything. EV batteries and motors are temperature controlled (coolant).

ICE exhausts can get anywhere from 500-1000F and there’s the issue of backfiring / rich mix that can cause fires.

 

[MBCook]

I was always told to avoid leaf piles since you don’t know what’s hiding under them.

Generally, it’s not getting hot enough under the car to combust anything. EV batteries and motors are temperature controlled (coolant).

ICE exhausts can get anywhere from 500-1000F and there’s the issue of backfiring / rich mix that can cause fires.

That makes sense to me. The “you don’t know what’s in there“ is certainly a big factor as well, although not really one I was thinking of.

Then again if a neighborhood kid decides to bury themselves in a pile of leaves in the street I kind of feel like there’s a little bit of Darwinism going on if something happens. I’m not rooting for it, but it’s not exactly gonna feel like an accident.

 

[zvez]

That makes sense to me. The “you don’t know what’s in there“ is certainly a big factor as well, although not really one I was thinking of.

Then again if a neighborhood kid decides to bury themselves in a pile of leaves in the street I kind of feel like there’s a little bit of Darwinism going on if something happens. I’m not rooting for it, but it’s not exactly gonna feel like an accident.

darwinism is a wonderful thing, but you'd still be dragged thru the courts

 

[Teslaeata]

Eeeerrrrrrrrrrmmmmmmm, no!

underside of an EV far cooler than an ICE with an exhaust, cat & DPD at up to 700degC ??‍

 

[RickMachE]

Parking in leaves, not driving through.

 

[Teslaeata]

It’s that time of year around me when you see lots of piles of dry leaves in the street that just fell off the trees. I was always told never to drive through them in a normal car because the heat of the exhaust, especially the catalytic converter, would catch them and you could cause a fire that may include your car in the destruction.

Then I got to thinking… I’ve never heard anyone say whether it’s still a problem for EV‘s. The battery doesn’t get up to terrible temperatures. The brakes certainly can. I assume the motors get quite toasty.

I don’t intend to try it out, but it anywhere near as dangerous?

Brakes are stone cold even after long runs, cold to touch and the new thermal imaging camera illustrates after last 100-mile leg of a 560-mile day!

Look at tyre heat compared with disc/rotor, ignore the orange colouring of disc/rotor top right which is a reflection.

 

[Mach1E]

Brakes are stone cold even after long runs, cold to touch and the new thermal imaging camera illustrates after last 100-mile leg of a 560-mile day!

Look at tyre heat compared with disc/rotor, ignore the orange colouring of disc/rotor top right which is a reflection.

Yes, but 21 C isn’t starting any leaf fires. ?‍

Brakes do get a LOT hotter than that.

Quick google search- “The normal temperature for brake rotors on a car is between 250°F and 300°F. However, the temperature can increase to 600°F to 700°F if the brakes are overheating.”

Your thermal temps must be from a highway drive. My brake rotors would burn my hand if I touch them after driving in the city.

 

[Teslaeata]

Your thermal temps must be from a highway drive. My brake rotors would burn my hand if I touch them after driving in the city.

Because you’re an ANIMAL ?

 

[Teslaeata]

Yes, but 21 C isn’t starting any leaf fires. ?‍

Brakes do get a LOT hotter than that.

Quick google search- “The normal temperature for brake rotors on a car is between 250°F and 300°F. However, the temperature can increase to 600°F to 700°F if the brakes are overheating.”

Your thermal temps must be from a highway drive. My brake rotors would burn my hand if I touch them after driving in the city.

All which indicates EVs are far less likely to set leaves on fire than ICE.

“Driving through” leaves, per the OP, is very unlikely to present much of a fire risk without a flame.

Leaves need to be exposed to temperatures of 400C/750F for a long time before catching fire.

Even driving onto and parking on dry leaves wouldn’t place leaves in direct contact with brake disc/rotors as they’d need to be, and then the discs would need to remain at that temperature or higher which is impossible once no further heat is generated from braking when they will very soon cool.

AP Racing say race brake temperatures are 400-600C/750-1100F, brakes glow cherry red at around 600-700C/1100-1300F and disc face peak temperatures may be higher (than inner component temperatures) but will soon cool when braking ceases.

I’m sure we could all find some circumstance by Googling and listening ICE-age man and the anti-EV brigade where an EV might and only just might set alight leaves or represent a greater risk of fire or of anything than ICE BUT still no greater risk than an ICE here.

Keep searching and inventing scenarios and you may find something ?

 

[Mach1E]

All which indicates EVs are far less likely to set leaves on fire than ICE.

“Driving through” leaves, per the OP, is very unlikely to present much of a fire risk without a flame.

Leaves need to be exposed to temperatures of 400C/750F for a long time before catching fire.

Even driving onto and parking on dry leaves wouldn’t place leaves in direct contact with brake disc/rotors as they’d need to be, and then the discs would need to remain at that temperature or higher which is impossible once no further heat is generated from braking when they will very soon cool.

AP Racing say race brake temperatures are 400-600C/750-1100F, brakes glow cherry red at around 600-700C/1100-1300F and disc face peak temperatures may be higher (than inner component temperatures) but will soon cool when braking ceases.

I’m sure we could all find some circumstance by Googling and listening ICE-age man and the anti-EV brigade where an EV might and only just might set alight leaves or represent a greater risk of fire or of anything than ICE BUT still no greater risk than an ICE here.

Keep searching and inventing scenarios and you may find something ?

Oh I wasn’t suggesting that it’s necessarily a fire danger.

Just pointing out that your thermal of 21 degree C tires and “stone cold” brakes is way off.

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