Can Wrapping Your Car Keys In Foil Prevent Your Car from Being Stolen?

Car owners typically take steps to ensure car safety and secure their vehicles from vandals and thieves. They are even going to lengths that seem somewhat strange to many people. Snopes checked into a Yahoo ad after it claimed you could wrap your keys in foil to help prevent car theft.

They found that nothing in the slideshow said anything about using tin foil. However, does wrapping your keys in foil really help protect you from car theft? Here are what Snopes found and other ways to protect your car.

Why would someone wrap a key fob in foil

A variety of car keys in the form of key fobs and more.
Car keys | Getty Images

The fundamental reason wrapping your key fob in aluminum foil as a protective cover works is because key fobs use an electronic signal to lock and unlock car doors while sounding the horn. In the past, people used aluminum foil on TV antennas to receive a better signal. However, aluminum does also block cell phone signals and some radio waves.

How electronic key fobs work

Key fobs have buttons that lock and unlock the doors and trunk of your vehicle, as well as a button that sounds your horn. Some more modern key fobs can even start your car before entering the vehicle. All this is possible by using radio waves to communicate with a reader located in the door latch.

There’s also a radio frequency identification system (RFID) that operates like an electronic barcode. You may have heard or seen the term RFID in relation to wallets, as some wallets have an RFID blocker to prevent electronic scanners from reading your credit and bank cards.

Snopes’ findings

As the people of Snopes noticed that the idea of wrapping car keys in aluminum foil had appeared in the news before, they decided to do a little digging. They noticed that, while still somewhat rare, some criminals hack into the key fob’s signal and steal someone’s car.

They then tested three vehicles and discovered that it’s sometimes true that wrapping a key fob in aluminum foil kept the signal contained. They tested a Toyota, Mazda, and Subaru. 

For the Toyota, the wrapped fob wouldn’t send a signal to the car, even when it was inches away. The wrapped Mazda fob wouldn’t function a few feet away, while the wrapped Subaru fob would function 10 feet away. They concluded that the method’s success depended on the make of the car, the year of the car, and the thickness of the foil.

How To Protect Your Key Fobs

The only real way to protect your key fob against signal hackers is to prevent the signal from being detectable. You can do this by placing the fob in a Faraday bag to keep in your wallet, purse, or home. There are also small Faraday boxes for key fobs and garage door remotes.

Other ways to prevent vehicle theft include:

  • Parking in well-lit areas
  • Install a vehicle immobilizer system
  • Don’t leave your keys or spare keys in the vehicle
  • Steering wheel claw
  • Lock your doors
  • Install a kill switch

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