Would Your Car Survive an EMP Attack?

There are a few competing schools of thought regarding the effects of powerful electromagnetic pulses, either in the form of an Electromagnetic Pulse (EMP) attack or a natural phenomenon like a coronal mass ejection, on cars and trucks.

The conventional wisdom is that if your car relies on any delicate electronics, it would be toast in the wake of an EMP attack. This is the origin of the idea that cars built during and after the 1980s aren’t EMP-safe. However, real-world testing with EMP simulators has yielded mixed results.

Regardless of which camp you fall into, the bigger issue is that after a large-scale EMP attack, or a devastating coronal mass ejection, it is very likely that fuel production and distribution systems would be knocked offline.

So in the absence of some type of alternative fuel source, you would very likely find yourself stranded even if your car were to survive an EMP attack.

What Is an EMP?

EMP stands for electromagnetic pulse, and it basically just refers to a huge burst of electromagnetic energy on a scale that is likely to interfere with, or permanently damage, any electronics that it comes into contact with.

Solar flares have created EMPs that damaged satellites in the past, and weapons have also been developed to remotely disable vehicles by generating a strong electromagnetic pulse.

When people talk about an EMP attack, they’re referring to one of two different types of weapons. The first is nuclear in nature, and it involves the sudden release of a tremendous amount of electromagnetic energy following a nuclear detonation.

In one common doomsday scenario, several nuclear weapons, referred to as high-altitude electromagnetic pulse (HEMP) devices could be detonated over the continental United States. This would subsequently take out the entire power grid and damage unshielded electronics throughout the country.

The other type of EMP attack involves a non-nuclear weapon. These devices use non-nuclear methods to achieve the discharge of a tremendous amount of electromagnetic energy, typically with the use of components like a capacitor bank and microwave generator.

In any case, the fear associated with an EMP attack is that the surge of electromagnetic energy can interfere with the operation of electronic devices. Some devices could shut down temporarily, others would malfunction during or after the attack, and complicated electronics and computing hardware may be permanently damaged or destroyed.

EMP Safe Vehicles

Since the idea behind an EMP attack is to take out delicate electronics, and modern cars and trucks are chock full of electronics, the conventional wisdom says that any car built since the early 1980s is likely to be vulnerable to an EMP. By the same logic, newer vehicles that are even more reliant on electronics are much more likely to be damaged in the event of such an attack.

Modern vehicles do use a number of electronically-controlled systems, from fuel injection to transmission controls and everything in between, so it only seems logical that a powerful EMP would turn any modern vehicle into an expensive paperweight by shutting down the electrical system or permanently damaging it.

According to this logic, older vehicles that don't make use of complex onboard electronics systems should be safe from an EMP attack. However, the small amount of real-world testing that has actually been done doesn't necessarily line up with these very reasonable assumptions.

Automotive Vulnerability to EMP Attacks

According to data from the EMP Commission, conventional wisdom may be wrong, or at least not entirely correct. In a study released in 2004, the EMP Commission subjected 37 different cars and trucks to simulated EMP attacks and found that none of them suffered permanent, crippling damage, although the results were somewhat mixed.

The study subjected vehicles to simulated EMP attacks both while shut off and while running, and it found that none of the vehicles suffered any ill effects if the attack occurred while the engine was off. When the attack occurred while the vehicles were running, some of them shut off, while others suffered other effects like erroneously blinking dash lights.

Although some of the engines did die when subjected to an EMP, each of the passenger cars tested by the EMP Commission did start back up.

The study findings suggested that 90 percent of the cars on the road in 2004 would suffer no ill effects at all from an EMP, while 10 percent would either stall out or suffer some other ill effect that would require driver intervention.

That number has no doubt gone up in the intervening decade since there are more cars on the road today that make use of delicate electronics, but none of the vehicles tested by the EMP commission suffered permanent damage.

Why Didn’t the EMP Commission’s Tests Permanently Damage Automotive Electronics?

There are a few possible reasons why the electronics in our cars may be a little bit more robust than we give them credit for. The first is that the electronics in cars and trucks are already somewhat shielded, and they also tend to be a little more robust than most consumer electronics due to the harsh conditions they are subjected to while on the road.

Another factor that may help protect the electronics in a car is that the metal body of the vehicle can act as a partial Faraday cage. This is why you can survive your vehicle being struck by lightning, and it’s also why car radio antennas are located outside, rather than inside, the vehicle. Of course, your car isn’t a perfect Faraday cage, or you wouldn’t be able to make and receive cell phone calls.

Better Safe Than Sorry in an EMP Attack?

While none of the cars tested by the EMP Commission in 2004 suffered permanent or crippling damage, and only one of the trucks required a tow, that doesn’t mean cars are totally immune to EMP. Vehicles built in the time since the EMP Commission study could be more vulnerable, due to more onboard electronics, or less vulnerable, due to more robust shielding from electronic interference.

In any case, the fact is that while it’s possible for an EMP to damage the electronics in a car or truck, there are no vitally important electronics to damage in older vehicles. That's where the old adage of "better safe than sorry" comes into play.

The Safest Vehicle After an EMP Attack

While real-world testing seems to indicate that most modern cars and trucks will start back up and drive just fine following an EMP attack, there are a few other factors that warrant consideration.

For instance, older cars and trucks are simpler, easier to work on, and often easier to find parts for. And in a worst-case scenario, following an EMP attack, there is a definite argument to be made for an older, reliable vehicle that you can work on yourself.

The other main issue to consider is that if the entire power grid is taken down, fuel production and supply will also be dead in the water until it comes back up. That means you'll be stuck with whatever fuel you have on hand, which is where the knowledge of how to make ethanol or biodiesel at home could come in very handy.