Fact Check

Holding a Key Fob to Head Boosts How Far Away You Can Remotely Lock/Open a Car?

And it's reportedly 100% safe.

Published Jan 2, 2024

 (Top Gear on YouTube)
Image Via Top Gear on YouTube
Claim:
Holding a car's key fob to your head increases the range from which the fob can lock or unlock a car.

In 2007, famous "car guy" Jeremy Clarkson announced to the Top Gear audience that he had learned something that morning that he found so astonishing he had to test it. It's an oft-repeated claim, spread more like urban legend than actual fact: You can extend the range from which to lock or unlock your car simply by holding your key fob to your head.

For Clarkson, the trick worked (although we must admit, the camera quality and positioning is a bit shoddy). The hack has also been shared in outlets like The New York Times and on social media.

But why does it work? As it turns out, there's a different YouTube video featuring a physicist explaining that.

To make a long story short, holding the key fob to your your head turns it into a temporary antenna, taking whatever signal was present and amplifying it. This works because of how water interacts with electric fields — and especially nicely with heads because of how much water they contain (around 73%, according to Healthline).

An experiment conducted by a user on the Physics StackExchange forum was able to further clarify the best position for the key fob: pressed up against the temple of the head. Although the technique is completely safe, the user also reported the best method that didn't involve putting the key to your head: pointing your remote directly at the car at an average body height. Citizen science at it's finest.

Sources

“Body Water Percentage: Average, Ideal, How to Maintain and Determine.” Healthline, 10 July 2019, https://www.healthline.com/health/body-water-percentage.
Boutin, Paul. “Low-Tech Fixes for High-Tech Problems.” The New York Times, 18 Feb. 2009. NYTimes.com, https://www.nytimes.com/2009/02/19/technology/personaltech/19basics.html.
Jeremy Tests Central Locking Range | Top Gear | BBC Studios. www.youtube.com, https://www.youtube.com/watch?v=_jACSPipPSE. Accessed 2 Jan. 2024.
Mueller, Chris. “Answer to ‘Why Does a Remote Car Key Work When Held to Your Head/Body?’” Physics Stack Exchange, 16 Mar. 2014, https://physics.stackexchange.com/a/103759.
Stromberg, Joseph. “Can’t Find Your Car? Hold Your Key Fob up to Your Head. (Really.).” Vox, 22 Nov. 2014, https://www.vox.com/xpress/2014/11/22/7259707/car-key-fob.
The Science Behind Why Your Head Can Boost A Car Key Fob Signal | News | CarThrottle. 23 Sept. 2021, https://www.carthrottle.com/news/science-behind-why-your-head-can-boost-car-key-fob-signal.
Unlocking a Car with Your Brain - Sixty Symbols. www.youtube.com, https://www.youtube.com/watch?v=0Uqf71muwWc. Accessed 2 Jan. 2024.
“YSK That Pressing Your Car Key Fob up against Your Temple or under Your Chin Extends/Increases the Range of It’s Signal to the Car.” Reddit.Com/r/YouShouldKnow, https://www.reddit.com/r/YouShouldKnow/comments/oqvq0s/ysk_that_pressing_your_car_key_fob_up_against/.

Jack Izzo is a Chicago-based journalist and two-time "Jeopardy!" alumnus.