Will Cars Still Run After an EMP? The Surprising Truth

Imagine every electronic device going dark in the blink of an eye. Forget about luxuries such as your smartphone or wi-fi, and imagine basic necessities like power, heat, supply chains, and infrastructure rendered completely inoperable. Imagine communications completely disabled.

This is the potential effect of an EMP, or an Electromagnetic Pulse. An EMP could alter the landscape of the entire power-grid in an instant, rendering whole cities blacked out for prolonged periods or even permanently. Food, fuel and water may very well become inaccessible when the power has failed completely.

An EMP event is quite scary, but would all cars on the roads just come rolling to a stop when an EMP strikes? We rely on vehicles for everything from getting groceries from the store to maintaining resupply chains that make our modern life possible. If they were to stop, getting out of town would no longer be an option for most people.

For this article, we’ll look at whether a strong EMP would disable all vehicles, which vehicles are most likely to be safe from an EMP, and how you can safeguard your vehicle from an EMP attack.

What is an EMP?

An Electromagnetic Pulse, or EMP, is a burst of electromagnetic energy. While energy is always in motion around us, an EMP is specifically notable for causing electronic disruptions by inducing current into electronics, sometimes severely damaging or destroying them. In extreme cases, an EMP can even knock out the power grid, or worse.

There are two main types of EMPs: natural and man-made. A bolt of lightning or a solar flare can cause an EMP, for example. The massive increase and change in electromagnetic energy as a result of a lightning bolt is a naturally occurring EMP. Solar flares causing highly charged atoms to shoot at high speeds from the sun towards the Earth is another form of a natural EMP.

Perhaps the best-known example of a man-made EMP source is from a nuclear blast. A nuclear blast shoots off multiple pulses of energy in its wake; these varied waves of energy cause significant disruptions to nearby electronics. Here is a more detailed (and scientific) explanation of EMP’s and how they damage electronic devices.

A city is dark an an EMP attack.
A major city after an EMP is a dangerous place to be—especially if you’re without a working car.

Many people are understandably concerned over EMP devices that are specifically designed to knock-out power, which are also known as High Altitude Electromagnetic Pulses, or HEMPs. A HEMP could either be a nuclear bomb detonated high in the atmosphere as a weapon or a device designed to knock out infrastructure and electronics without the heavy casualties of nuclear warfare. HEMPs can affect a much larger area in concentric circles from the blast. The area of effect would depend on how high in the atmosphere the device detonates. The US Congress received a detailed report on HEMP effects in 2008.

EMP attacks are not relegated to the realm of Science Fiction. A solar flare on March 13th, 1989 knocked out a large portion of the Canadian power grid. Lightning routinely damages electronic devices, although on a much more localized scale. British scientists, unaware of the electrical damage nuclear blasts would cause, suffered a massive instrument failure (they called it ‘radio flash’) after their initial nuclear weapons tests in the 1950s. These events happened and they can certainly happen again. It’s a good idea to understand them and understand what EMPs are capable of.

Would an EMP Attack Disable All Vehicles?

No, an EMP attack would not disable all vehicles. According to a study conducted by the United States EMP Commission, only about 1 out of 50 vehicles are likely to be rendered inoperable. The effects of an EMP on hybrid and electric vehicles, however, have yet to be studied and are currently unknown.

Questions about the potential damage to vehicles in the aftermath of an EMP are quite common. An exhaustive study by the EMP Commission to determine the effects of an EMP on the United States (available here) was conclusive: most vehicles would survive an EMP.

U.S. EMP Commission Test Results – Key Points

  • 50 vehicles built between 1987 and 2002 were exposed to a spectrum of EMP blasts (up to 50kV/m in strength).
  • 3 out of 50 vehicles shut down while driving.
  • All 3 of these vehicles continued rolling until they safely coasted to a stop.
  • 1 of those vehicles was disabled completely and would not restart.
  • 2 of those vehicles restarted without an issue.
  • Many nuisance issues arose from the 50 exposed vehicles including radio interference, strange and erratic behavior from headlights, turn signals, or brake lights, and one vehicle needed to have its dashboard replaced

The EMP Commission believed there was a potential for unnecessary deaths from vehicles if the vehicles were exposed to an EMP burst which exceeded 25kV/m. The potential for death and serious injury would not come as the result of an electronic failure, however, but rather due to potential accidents that vehicles slowing down suddenly could cause, especially if those vehicles had issues with their brake lights.

The EMP test indicates that roughly 15% of running vehicles may shut down if exposed to an EMP blast at or over 25kV/m over a wide range of area. In other words, short of a massive solar flare, only a nuclear explosion or purpose-built EMP would create the kind of pulse needed to cause the shutdown effect to occur.

When considering the EMP Survey by the EMP Commission, there are a few points to think about. First, this study finished in 2004. Second, the cars used in the study were older models, built in a range from 1987 until 2002. Third, we do not know which specific vehicles the Commission conducted these tests on, as the Commission never released information on car makes or models. Fourth, cars have developed far more complex and integrated electrical systems since 2002, the latest model year tested. Finally, the test does not appear to have been recreated and the results are not scientifically verified as a result.

Video: Testing a Modern Vehicle in a Lightning Strike

This video from the British car show Top Gear actually explains this concept quite well. Volkswagen has a purpose-built facility to test their cars against potential lightning strikes with charges of up to 800,000 volts. After the bolt hits, the car starts right up. Modern cars can survive a multitude of electrical issues without failing.

Resilience of Modern Vehicles

By design, modern automobiles can survive extreme temperatures and other harsh conditions. Modern cars have many fail-safe systems in case of electrical or mechanical failure. As a result, most cars will continue to run without major issues, even in the face of an extreme electrical disruption.

Many commentators on this subject believe the EMP study is out of date. Specifically, there’s a theory that older vehicles lacked the integrated computing systems and complex electrical engineering that modern cars have. While this is true, cars have had computers since Volkswagen introduced one to operate their electronic fuel injection (EFI) system in 1968. Engine Control Units (ECUs) have been widespread since the 1970s. It is safe to assume every vehicle in the EMP Commission Study had an ECU in one form or another.

In one sense, it’s understandable that people worry about modern vehicles being more electronically sensitive to EMP damage. However, modern vehicles have more protective shielding, grounds, and plastics to replace metals now than they’ve ever had in the past. In almost all cases, modern cars should be more capable of withstanding electrical interference than they have been in the past. Except of course, if you are talking about vehicles manufactured before ECU’s and were largely mechanical based in their functions.

So, in summary, EMPs will not disable most vehicles. Many modern vehicles that would seem unlikely to survive the EMP probably will survive the EMP, but we don’t currently have sufficient testing to verify that.

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The Strongest Possible EMP Attack

Let us consider the ‘doomsday’ scenario for a moment. An EMP hits and the power goes out. For the sake of argument, let us assume that the EMP completely knocks out the entire power grid of the United States and that no other country is willing or able to divert power to the country. Manufacturing crumbles, international trade evaporates, and America is transported back to the 1800s.

Realistically, only a nuclear explosion at a specific altitude or a strong solar flare could cause that sort of disruption. Anything with long wires leading to it will be especially vulnerable to this (such as the power grid—or anything connected to it). That’s because the long power lines will act like a giant antenna and gather massive amounts of energy flowing through the atmosphere, channeling it into whatever they’re connected to.

Modern motor vehicles do have a lot of wiring in them, but this wiring doesn’t travel out from the vehicle and is, generally speaking, coiled tightly inside the metal box that is your car’s shell. A HEMP designed to knock out power will probably fail to generate more than 25kV/m outside of the immediate blast area, meaning most cars will survive without any issues at all, as the testing done by the U.S. EMP Commission showed.

Generally speaking, your vehicle will be the least of your concerns in this type of situation. The electrical system of modern cars features much better shielding. The electrical shielding your car has will not prevent the inevitable part failures all cars experience. The lack of spare parts or able mechanics will likely ultimately sink your vehicle, not the EMP itself.

What Type of Car is Most Likely to Survive?

In a doomsday EMP scenario, the vehicle most likely to be viable is an older model diesel vehicle that lacks electronics. Since the roads will not have maintenance you will probably want a 4×4 vehicle that can go off-road when necessary.

Most modern diesel vehicles are just as technologically advanced and electronically complex as their gasoline counterparts. The big difference between diesel and gasoline is in finding fuels in case the power goes out. A gasoline engine requires highly refined and specifically processed fuel. Diesel engines can run on almost any type of fuel, including bio-diesels like algae and vegetable oil. Yes, vegetable oil.

While both carburetor-based and fuel-injection vehicles are likely to survive the EMP, vehicles utilizing carburetors are far less reliant on modern electronics than fuel-injected vehicles are. If you worry about the lights going off and never coming back on, you should avoid fuel-injection vehicles.

“If you’re serious about having a vehicle that will survive massive EMP damage, then you’re looking for a naturally aspirated diesel engine from before about 1990. A 4×4 is probably a safer bet than a front or rear wheel drive.”

How Does the Military Protect Against EMPs?

The military is an interesting case study in EMP defense. The military not only faces the potential for natural phenomena, like a lightning strike or solar flare, but they also face the possibility of fighting against a foreign power that uses weapons to disrupt communications, navigation, aviation, and other critical aspects of warfare.

The military primarily uses a simple Faraday Cage to protect its equipment against the potential damages of an EMP attack. A Faraday Cage is a simple construction of grounded metal surrounding sensitive electronic wiring and equipment. During a surge of electromagnetic energy, such as the most severe EMPs, military equipment is protected from damage by this simple Faraday Cage.

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Advanced equipment, such as jet-fighter planes, are mostly protected by the same concept. In both the case of a car and a fighter plane, military equipment is further designed and developed to operate independently of its electrical systems. Even if the electronics fail, there are several active fail-safes in place to operate both vehicles and airplanes by hydraulics and manual control, if necessary, to prevent a critical error and eventual crisis.

It should be pointed out that similar fail-safe systems are in place in civilian aircraft, civilian electronics, and yes, civilian automobiles.

Preparing Your Car for an EMP

Most vehicles will survive the doomsday scenario without missing a beat, and there isn’t much you need to do. The real threat to a vehicle after some kind of apocalyptic event is a lack of fuel and spare parts, not an electrical failure.

To prepare for the potential EMP disaster, you could stock up on parts that could commonly fail or might be required for routine maintenance. These include:

  • Spare fuel—treated with Stabil fuel stabilizer to extend its shelf life
  • Various required filters (air filter, oil filter, and fuel filter)
  • Oil change supplies
  • Battery
  • Alternator
  • ECU
  • Sensors
  • Any other on-board computers

Keeping regular maintenance items on hand, such as those required to complete an oil change, is a great idea. The other spare parts on this list might be a bit more expensive. You can find the spare parts you need by plugging your VIN into one of the many car parts websites and looking up replacement parts that fit your vehicle.

However, my favorite source for spare parts to have on hand in case of an EMP is a wrecking yard. Find a vehicle as close as possible to yours at your local wrecking yard and remove all the sensors you can find along with the alternator and ECU. It’ll be far cheaper than buying all brand-new parts.

How will an EMP affect batteries in your electronic devices or in storage? See How Would an EMP Affect Batteries here to find out, this is really important!

You may consider putting spare electronic engine components into a Faraday bag for further protection—that’s what I do. If you’ve gone through all this trouble to be prepared by buying a second set of vulnerable parts, you might as well go a little further by putting them in an EMP-proof Faraday bag such as these.

What precautions are you taking to help ensure you have transportation in an EMP strike? Share in the comments below!

John Walter

John Walter is an emergency preparedness consultant with eight years of experience and training in related fields. He is a passionate prepper living in the Sacramento area of California.

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