Bingley's question about the best size of fire extinguishers for cars made me wonder about something when you do discover a fire (usually under the car's hood), and as I did not want to hijack his thread, I thought I start a new one.

So...

You discover a fire under the hood of the car. It seems most people's first impulse is to get the hood open to get to the fire, and (if they have it) use an extinguisher.

But, is this the right thing to do?

IMO, keeping the hood closed will contain the fire and the smoke and CO/CO2 will tend to deprive the fire of oxygen, and slow it down. When you open the hood, the fire will flare up as all the fumes escape upward and oxygen flows in from the bottom. Now it is a bigger fire. So even if you have an extinguisher, opening the hood may just flare up the fire so it is totally out of control. . .better to just get everyone clear and to call for help and let the pros handle it. Leave the hood closed.

What do you guys think?

I used to work at a large American automaker's proving ground that had all sorts of experimental activity going on - so there was a higher possibility of engine fires there than in the outside world.

We were carefully instructed that in the event of an engine fire the FIRST thing we were to do before exiting the vehicle was to pull the hood release. The second thing we were to do was to get away from the vehicle and call the emergency phone number. We were NEVER to attempt to open the hood.

They told us that the heat of a fire could quickly heat up the hood release cable clamps making it almost impossible to open the hood without massive damage to the vehicle.

Let the firefighters pop the secondary hood release, open the hood, and pressure wash the engine - or what's left of the engine.

I would like to note the original post has two separate and opposing questions really.

1. With regards to safety and survival, is it better to open the hood or keep the hood closed while getting far away? (I say the answer to this question is keep the hood closed and get far away, and pop the latch first if you have the time and nerves to do so.)

2. With regards to putting the fire out quickly without regards to the best safety, is it best to open the hood or keep the hood closed? (I say the answer to this is get that hood open somehow and get some extinguisher on that fire; and that's a job for a trained professional.)

I was taught to run away from your own car on fire, there is not enough time to locate what you need, just get out.

If it is someone else's car pop, not open, the bonnet (hood) and blow the extinguisher through the gap until it is empty, but be prepared, it will probably not be enough. Leave the opening of the bonnet to the professionals. Don't touch a cabin fire.

Last year a car in the road outside stopped with a fire under the bonnet, I dumped a 2kg CO2 extinguisher in to no effect then got a 6kg powder which did the job. By then the engine was a right off, just about everything non-metal melted.

The best solution that I have found after failing to put out an engine fire in a stranger's car with a standard fire extinguisher which didn't seem to want to operate very well on it's side or inverted, is to get an extinguisher with an attached flexible hose. That way, you could hold the extinguisher upright and bend the hose to where you needed to put it - either through a popped, but not opened hood, or from underneath the car, spraying upwards into the engine compartment.

I was told the following

If the fire is relatively small, and you have a large extinguisher, then open the hood just sufficiently to use the extinguisher. DO NOT fully open the hood until the fire appears to be out, and even then have a second unused large extinguisher to hand when eventually fully opening the hood.
Dry powder is considered the most effective type of extinguisher for vehicle fires but is also the most destructive. CO2 is fairly effective but disperses very quickly in the open air. Foam is effective.

If no large extinguisher is to hand, leave well alone and await the fire brigade.

If a vehicle is well alight then it is already a write off, but in most cases the fire should still be fought least it spreads to structures or other vehicles.
Perhaps surprisingly, water from a hose may be used on a vehicle fire, it is mainly rubber and plastic burning and not petrol.
Apply the water such as to cool surfaces and prevent the fire spreading.

I was told not to run. There is enough time to walk away to a safe distance and direction.


If you need significant time to locate what you need, you put it in the wrong place. Around here vehicles which are required to have extinguishers on board, must store them in an easily accessible place. When you bother to keep an extinguisher in a vehicle, it should be easily reachable. On a side note it should be regularly serviced or replaced too.

Most car fires you encounter are already involved, there's no fighting the fire or rescuing a burned up engine. Use a fire extinguisher if necessary and convenient to rescue occupants, by keeping flames at bay and releasing or cutting their safety belts.

"Run Away" like in Monty Python "Run Away"

Run Away, Monty Python

Does German humour allow Monty Python to be available?

As Tim the Enchanter said, "So! Brave knights! If you do doubt your courage or your strength, come no further, for death awaits you all."

Jeanette Isabelle

The movie is full of public service announcements such as what not to do when coming to a washed out bridge.

King Arthur: I have no quarrel with you, good Sir Knight. But I must cross this bridge.

Black Knight: Then you shall die.

Jeanette Isabelle

Don't most car fires start under the hood? How do you physically open the hood when as soon as you pop the first latch (from inside the car) the second latch is in flame? I've got a pair of Nomex gloves in my truck, and while they do a good job at protecting against flames, the heat from the fire finds its way through. So while the question of should you open the hood is the topic; how would you open the hood?

The fire extinguisher, gloves, rescue knife and tools in my truck console are not for my truck, they're for somebody else's...

Generally Monty Python does not blend in well with German humor. Much of the humor got butchered up in translation anyway. I only started liking it, when my command of the British language became good enough to actually understand it.
In the case of car fires running might be a bad idea as you might be in area with fast moving vehicles. So get out, make sure the other passengers made it out too, look for a save path of retreat and then walk away. On German roads people get killed for hurrying in the wrong direction - not on purpose but that does not make much difference to them.

As others have said, leaving the hood down is the best advice. Open, it's a perfect chimney. But that advice may be counter-intuitive, because what what you'll likely see is a lot of smoke, not flames. The temptation is to open the hood and find out what's going on. Then, poof!

For fighting a vehicle fire? From the few incidents I've seen, no fire extinguisher is big enough. A 4-pounder is the "entry level" size, and they're not handy to schlep around in a passenger vehicle. Better to spend the money on a more robust insurance package and walk away.

The nightmare scenario is coming across a wreck on fire with people trapped inside. A small fire extinguisher and rescue tools may help, but the odds are against you. I vaguely recall that one of our members faced this some years back. May heaven/fate preserve us from such a no-win scenario.

Anyone trying to fight a vehicle fire without proper training, protective gear, and backup personnel (i.e. - a fireman on duty, in their official capacity) would be a total fool. You're probably not going to save the car. You're probably going to severely burn or kill yourself. Just too many hazards there - Open the hood and the flames flash up and into your face, potential fuel spills, pressurized "5 mph bumpers" exploding outwards and breaking your legs, hybrid car batteries showering you with who-knows-what's-inside-them ... No thanks. There are enough Darwin Award contestants in the world without me jumping into the fray.

Just (1) get yourself and any other car occupants away to a safe distance, (2) call the fire department, and (3) file an insurance claim. You can only do (3) if you are still alive to fill out the paperwork.

And most certainly, don't go and fling that hood wide open. Not even the dumbest of the fire fighter school rejects would do that.

As many have said, a car fire can be a dangerous thing. Those dangers have been pretty well covered in others posts.

Rubbers, plastics and other synthetics tend to burn less completely than ordinary combustibles. The thicker, darker smoke is not only much more toxic but it is also more explosive than cleaner burning fuels. Smoke from a typical engine compartment fire could have a ignition temperature similar to propane, this is why it is not uncommon for the fire to "explode" when the hood is opened completely.

So, the best advice is what a lot have been saying: pull the hood release and get away from the car and the smoke. Hood release usually fail in a car fire, and pulling it before you exit the car will make it much easier for the fire department to open the hood.

Fire extinguishers are just about useless in car fires that are well involved. They work well for small fires that you can easily access, when used correctly. Often when we get on scene, we will find multiple used fire extinguishers laying around the front of a car that had no effect on the outcome.

Good comments -- sobering. I hadn't considered all the stuff in modern cars that creates additional hazards in a fire. It's not at all like the old days with simple engines, lots of room, and a direct line of sight to the problem.

Uhm, one thing I forgot to mention in my earlier post. The VERY first thing you should do if you think your engine is on fire is to shut off the engine.

Then pull the hood release (from near the driver seat), get away from the vehicle, and call 911.