In the most recent adaptation of War of The Worlds, at one point everyones cars stopped working. Except for the protagonists, which had just been repaired. Was this ever explained?


The mechanic was fixing the car the moment the EM pulse was fired, and replaced the solenoid after it happened, meaning the solenoid wasn't destroyed by the pulse and the car worked. Cruise's character realizes this and tells the mechanic to replace the solenoids on the stalled cars to fix them.

Now I don't know much about the mechanics of internal combustion engines, so I can't really vouch on how accurate this would be in real life.

  • 4
    Well, it would probably work to fix an old car (e.g. from the 1950s) if just the solenoid was fried; anything recent would get all the integrated circuits fried by a much weaker EMP. Oh, and the spark plugs - those would certainly get fried as well if the solenoids would (but they're much harder to replace properly, which would probably break the movie's Rule Of Cool). Mar 4 '12 at 20:11
  • 3
    Wouldn't uninstalled solenoids and sparkplugs (in unshielded cardboard boxes) get fried as well? Mar 5 '12 at 1:49
  • 7
    @SystemDown Probably not. An EMP works by having a charge build up across wires. The shorter the wires, the less charge that can build up. Kind of like an antenna. Installed spark plugs are attached to the full wiring of the car, allowing the EMP to have a larger amount of metal to build up a moving charge in. Spare spark plugs have almost no wire to build up a charge in... just an inch or two. If a pulse could fry that, then it would be strong enough to literally liquefy the metal in the car frame, and be far beyond what is normally possible from an EMP. Mar 5 '12 at 2:58
  • EMP fries microprocessors by a sending a high voltage, low-amperage pulse through the circuits a speed faster than the current regulators in standard systems can block. The voltage and amperage is high enough to destroy the microscopic circuit traces on microprocessors but to low to damage older, all analog system which simply have much bigger wires in their circuits. Since government regulation requires that all cars built since circa 1980 have computers in them for fuel efficiency and pollution control, all modern civilian vehicles are susceptible to EMP. A classic 1968 Cadillac wouldn't be.
    – TechZen
    Jun 10 '16 at 19:35
  • Assuming they aren't all just piles of slag, anything with points (contact breakers) would still work.
    – Mazura
    Jun 29 '17 at 21:54

Unless there has been some major change in spark plug tech, even connected to the system its unlikely you could get enough power through the cables to fry them before the cables exploded. The solenoid is a couple of very long wires coiled around a fero core. Its an electromagnet that takes low amps through the switch when you engage it to connect a high amp switch for starting the vehicle. If an EMP would fry any basic electrical system it would fry electromagnets. The thing I'm uncertain of is if it would make any real difference if the solenoid was connected or not. And if not being connected would protect it I would think not being engaged should as well, so the only cars that should need it replaced would have been those attempting to start their engines as the EMP occurred. The thing most likely to happen is that electronics would fry due to the voltage spike throughout the vehicle's wiring. And that would be a problem even if the engine was off but may not be a problem for spares laying around.

  • 2
    This seems to be on the right track albeit a bit muddled up, maybe you could consider editing it for clarity?
    – Edlothiad
    Jun 29 '17 at 8:50

EMPs actually don't work on that particular model of car, this was clearly explained. There were other same modelled cars driving around.

  • 3
    Do you have any evidence for this such as the relevant quotes and/or a scene link? Also some evidence of the cars still driving after the scene blast would be nice i.e. screenshots or scene links again. If so can you edit this into your answer?
    – TheLethalCarrot
    Jan 18 '19 at 10:30

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