Car chase --> ?? --> car on fire?

Factual Questions
1

A two part question:

First, what are the most plausable ways for a car moderate-speed chase to end in one of the cars being on fire? Not for the car to explode on impact action moviestyle, mind you, but for there to be fire that would threaten the life of the driver. (I assume that in all situations there needs to be damage to the gas tank, or at least gas lines. is this a sound assumption?)

  • the car slamming into a stationary object such as a tree, bridge abuttment, or wall?

  • bursting through a guardrail, becoming airborne, having a long drop, and landing very hard when the vehicle hits the ground?

  • after rolling over?

  • something else I haven’t thought of?

And second: Any idea how long one might have to rescue a person from each burning car situation? Or not to rescue them, as the case may be. Ideally, given I’m hoping to kill a character off this way, I’m hoping that there’s a cause for fire that might give potential rescuers 2-10 minutes to haul the driver out of the car.

2

Have this character drive a Ford Pinto, and then get the car rear-ended by a pursuing police car. Of course, that may be telegraphing your character’s impending death a bit too obviously…

More seriously, as a non-expert I’d find it plausible that there could be a car fire accompanying any collision serious enough to trap the driver. I would further guess that your second scenario could easily produce a car fire, since the gas tank and fuel lines are located on the bottom of the car and could be compromised by a hard landing on uneven ground (so the suspension doesn’t absorb the impact).

3

If the police put out spike strips to rip the tires, and the driver keeps going on the rims, there will be quite a few sparks generated, which could easily start a fire if the gas tank is punctured by some means.

4

The most common cause of cars catch fire during chase is a flat tire bursting into flames. This is usually accompanied by a failure of the braking system with the brake fluid also catching fire. I watched 3 straight hours of The Worlds Best Police Chases on TruTV a few weeks ago. In all but one of the chases that ended with the pursued car on fire was caused by a flat tire or 2. The only chase that had fire not caused by a flat was brainiac that thought hitting a gas pump at 30 mph would make the police quit chasing him. He forgot about the heavy steel pole embedded in concrete on the other side of the pump.

5

Just remember, it takes sparks or a flame to ignite gasoline fumes. So spilled gasoline and a passing driver throwing a cigarette out the window won’t work.

A big puddle of spilled gasoline and a passing driver dragging his tailpipe throwing sparks might cause ignition.

6

Point 1:

The usual routine in a car chase is that the driver is driving very aggressively and for a long time. Eventually the brakes and/or tires overheat from being used far harder than they were designed for. If a tire blows out & the driver keeps going, the shredded tire will really create a lot of heat while flapping, then the driver will be driving on the metal rim, which also generates a lot of heat & sparks when it skids.

So eventually one or more tires catch fire.

As well, if the driver runs over some obstacles or curbs, whatever it is may scrape the underside of the car. This will dislodge greasy, oily mud & gunk stuck to the underside & create sparks at the same time. It may also damage something along the bottom of the car, creating an oil or fuel leak. Which may be ignited by the sparks from the next obstacle crossing. Or from the tires.
Point 2:

Burning cars don’t explode, except in Hollywood. In the real world they burn for many minutes. A fire under the hood of a stopped car may burn for 10+ minutes before the cab becomes unsurvivable. Once the cab interior (plastic, upholstery, etc.) gets going, then you’re talking just a minute or two to get out before being cooked.

But cars are designed to contain a fire in the engine compartment so it doesn’t get into the cab. Hence the term “firewall” for the metal plate separating the two.

A simple crash, even a really spectacular end-over-end shedding parts crash, usually doesn’t end up with a fire unless there was open flame before the crash.

Having just hot brakes and tires, a hot engine, and open gas lines or gas tank when everything stops moving usually does not result in a fire starting. There’s some risk of one but it’s very far from a sure thing.

So you could have an extended chase leading to overheating brakes/tires leading to a tire fire, leading to the driver either crashing moderately or simply just pulling over & then in their drug- or adrenaline-induced haze, sitting there until overcome by the smoke & toxic plastic fumes from the fire. Once the car is really burning, the police won’t be able (willing?) to get the driver out. Even though a fire dept team could douse the flames & get the guy out in less than a minute if they were already there and set up. Which they’re not.

7

Belated edit: Must type faster or say less. 4 posts snuck in there while I was banging away. :slight_smile:

8

Did anyone see the Christina Ricci movie Pumpkin? A great film, but the car in that one goes sailing off a cliff and explodes not once, but twice on its way down before it ever hits the ground.

I figured it was friction with the air. :smiley:

9

I know. This story is set in NH, and if the car does any off-roading at all, it’s bound to encounter the state’s more reliable crop: rocks. Plenty of things around here to create the necessary sparks :slight_smile:

10

Does the car have to be on fire? A blown transmission hose makes a for an spectacular smokescreen. It could also lead to an impressive fire after somewhere in the 3-9 minute range.

11

Well, I imagine it going like this: protagonist and the cop are after the bad guy, and he takes off like a bat out of hell. They lose him for X many minutes because the ladies are not driving at an insane speed (weather or traffic from one of those stupid holiday parades they’re so found of here could slow them down, potentially), and when they finally find him, the car is on fire. They argue about whether or not to try to rescue him, and decide not to. I’m trying to fill in what happens between when they see him race off and when they find him trapped in the burning car.

12

An easy fire resulting from a crash…

Driver is smoking a cigarette, car has many greasy fast food bags under and behind the seats. The impact jars the cigarette out of the driver’s mouth and under the seat, where it lands on one of the bags.

I was present when some teenagers were sitting side by side in their cars tossing lit matches at each other. One match went in the back window and landed on a newspaper tucked under the seat. Within 2 minutes, the interior was fully engulfed.

13

Is it a stolen car? It’s not that uncommon for thieves to steal a car, drive it around and do what they want with it for a bit (drug deal, getaway car for a robber, etc), then set it on fire to remove all evidence that they were in the car. If the thief was on his way to drop off the car somewhere and set it on fire the car could have gasoline cans and all sorts of flammables in the back seat.

They found a burning car with a dead body in it near here a few weeks ago. Many years ago, a friend of mine had his SUV stolen. Once they were done with it, the thieves set it on fire and sent it rolling down a hill.

Generally speaking, cars that slam into trees, go through guard rails and drop a long way, or roll over don’t burst into flame. Even though it is possible (if rare) for a car to catch fire in one of these style wrecks, if I read one of these I would think “typical Hollywood nonsense”.

As others have mentioned, I’ve seen cars on long chases catch on fire after they’ve been running on rims and throwing sparks for miles and miles. I’m having a hard time picturing the car burning and the character still inside of it though. Usually the cops will yank the person out of the burning car once they get the car to stop.

An electrical problem can also cause a car to catch fire. I was going home from a college class I was taking (many many years ago) and the car in front of us suddenly pulled over and everyone inside hopped out. There wasn’t any flame yet, but the inside of the car had quickly filled up with smoke. The car went from “gee that’s a lot of smoke” to “holy crap the car is completely engulfed in flame!” in a surprisingly short amount of time. By the time the fire department got there the car was pretty much gone and they just let it burn. The car was in a field so it wasn’t going to hurt anyone or anything.

I’m picturing the character going down a long, steep hillside (crashing through trees, etc), getting pinned by a tree when the car finally does stop, and then smoke starts coming out from under the dash, slowly at first, then worse and worse until flames start. The cops have to walk down to the crash, and by the time they get there the car is engulfed in flames. You could do this same basic scenario with the flat tires and sparks causing the flame instead of an electrical fire, too. The long wooded hillside would give a plausible delay from the time of the crash to the time the cops can reach the scene and yank the character from the vehicle, which gives you time for a nice fire to develop.

14

I was driving a pickup truck that had a fire started by redlining the engine. I believe it was a throttle cable that got stuck wide open while I was passing, and it took few minutes to get across five lanes of rush-hour freeway traffic to the shoulder. I had to shift into neutral to avoid running into cars ahead of me (brakes were starting to fade), which let the engine rev too high for too long; by the time I got the truck stopped, the engine compartment was smoking, and it was in flames by the time the firefighters showed up.

15

A stuck throttle also will cause a lot of people to panic. That might be the reason the character crashes.

16

If you make it any older car (doesn’t even have to be a Pinto), you’ll get a lot of gas spilled out if the thing goes upside down, since it will run out of the vented gas tank and the open vented carburetor. Bursting into flames after a crash was a lot more likely in the old days!

17

I followed a van driving down the motorway that had a dragging exhaust - it generated an impressive shower of sparks. If the fuel tank was leaking…

I would have the escaping driver crash over a couple of speed bumps or curbs - enough to dislodge the exhaust and damage the fuel tank. A few seconds later, the back of the car is smoking and burning, the driver panics at speed and drops into a ditch, getting trapped and making rescue difficult and risky for the pursuers.

Si

18

I’m not sure, but step 3 is profit.

19

What about a severely damaged road instead of curbs and speedbumps? I don’t know what roads are like in other places, but a lot of them are in terrible shape here, potholes, cracks, and general unevenness (one of road had a sign to that effect. Gee given that there was about a six inch height difference between the two broken pieces, you think?) due to a couple of bad winters and several floods.

20

Oh, you live in England, too :wink:

Si