Sounding like something out of a sci-fi movie, Tesla’s Bioweapon Defense Mode is a feature that’s been available on Model S and Model X since mid-2016, and is now standard on both vehicles (as of July 2018).

Bioweapon Defense Mode is an option that’s definitely generated some publicity for Tesla, because it’s not every day you see automakers offering features that are useful in apocalyptic scenarios (hey there bulletproof Cybertruck 😉).

So, with that said—this post is part of our ongoing “Tesla Features Explained” series where we dive into a specific Tesla feature and break it down on an oh-so-nerdy level. Sound good? Alright, let’s jump in!

Bioweapon Defense Mode: How It Works & Why It Matters

Hospitals, clean rooms, and other facilities where air cleanliness is important all typically have one thing in common—the use of HEPA filters to scrub the air, and this is the same technology that Tesla uses in Bioweapon Defense Mode.

HEPA is an acronym that stands for high-efficiency particulate air. This is a considerably higher-performing filter than what’s used in most automotive systems. In fact, in the US there are strict standards for what constitutes a HEPA filter—the most important point being that they must filter out 99.7% of all particles that pass through that are greater than or equal to 0.3 micrometers. In other words, these are exceptional filters when it comes to purifying air.

And it’s these exceptional filters that are so crucial to protecting the health of Tesla drivers and passengers. According to data released by Tesla, people really don’t understand how bad polluted air is for to breathe. In fact, living in major cities with even moderate levels of pollution can reduce average life expectancy by months to years.

So, how does the system work? It’s actually quite simple—in Model S and Model X, a giant HEPA cabin filter is used that contains separate acid and alkaline gas neutralization layers to filter out a wide range of contaminants. When activated, Bioweapon Defense Mode recirculates air through the high quality HEPA filter, purifying the cabin air while avoiding the intake of contaminated outside air. Model S and Model X already use a secondary air filtration system, but when Bioweapon Defense Mode is activated, it adds the HEPA filter as another layer of filtration.

In addition to the multiple layers of filtering material, both filters for the interior air (including the HEPA filter) also contain activated carbon to remove a wide range of odors and gasses. On top of that, when Bioweapon Defense Mode is engaged, the fans operated at maximum speed to create positive pressure inside the cabin to minimize the amount of outside air that can enter—similar to the way a positive pressure room in a biohazard lab or hospital operates, preventing the backflow of bacteria and viruses into other parts of the building.

In order to switch on Bioweapon Defense Mode, you simply navigate to the climate control menu, tap “AUTO” and then tap the biohazard symbol.

OK Cool, But Does Bioweapon Defense Mode Actually Work?

This is the question that everyone asks—does it actually work? Sure, it sounds cool, but does it really work or is it just a gimmick?

Because Tesla is famous for bringing sci-fi like features to real life, it’s no surprise that yes—Bioweapon Defense Mode actually does work, and in fact—they’ve tested the heck out of it. One of the more famous tests involves Tesla putting a Model X inside a bubble that was contaminated with extreme levels of pollution (1000 micrograms per cubic meter) so they could determine just how effective it is.

It turns out that during the test, the Model X not only completely cleaned the cabin air to undetectable levels, but also scrubbed the air outside of the vehicle in the bubble, reducing the contaminant level by a whopping 40%.

So yes—not only does it work, but it actually leaves the outside air cleaner as well, which is quite the feat for an automotive filtration system! According to Tesla, it’s many hundred-fold better at purifying the air than other automotive systems.

One caveat, is that although Tesla states that it works against bacteria and viruses, many viral particles are smaller than the HEPA filtration limit, so it’s possible that there are some viruses that might not be filtered by Bioweapon Defense Mode.

So, if you’re thinking of using Bioweapon Defense Mode to filter out the Coronavirus (SARS-CoV-2) to protect against acquiring COVID-19, there isn’t enough research to suggest that you’d be safe for sure, although you’d be much better off than with a standard automotive filter system. Plus, the positive cabin pressure should help quite a bit as well.

However, it does seem to work extraordinarily well in normal (and even scary) use scenarios, like this California resident who used it to filter out smoke from blazing fires:

Bioweapon defense mode at its finest. from r/teslamotors

Which Tesla Vehicles Have Bioweapon Defense Mode? Does The Model 3 Have It?

At the time of writing, only two vehicles have Bioweapon Defense Mode—the Model S and Model X—it’s not available on Model 3 or Model Y, and not on the original Roadster.

According to Elon, the main reason for this is the fact that the filter is so big, it just won’t fit in the Model 3.

Because there are more Tesla vehicles in the pipeline, it’s possible that the new Roadster and the Cybertruck may have Bioweapon Defense Mode. The Cybertruck is certainly big enough, and with the new Roadster being such a premium vehicle, it doesn’t make much sense to leave it out there—but it will probably depend on size to some extent, as well as design and engineering constraints.

Are There Any Aftermarket Options?

No, at present time, there aren’t any aftermarket options for adding Bioweapon Defense Mode to Tesla vehicles—but there actually doesn’t have to be—because Tesla actually sells on upgrade in their official factory shop for only $500, which includes a firmware update to make it work properly. So, if it’s not something that came on your vehicle originally—don’t despair, you can actually add it after the fact.

However, as mentioned earlier, since mid-2018 Bioweapon Defense Mode has been standard on all Model S and X vehicles.

Tesla Bioweapon Defense Mode—Final Thoughts

Not only is this a cool feature, but it’s also quite practical, especially in uncertain times when you never quote know what types of pollutants might be in the are around your vehicle. And as shown by Tesla and a variety of user test scenarios, it absolutely works—so it’s a feature worth having, and potentially one reason to consider a Model S/X over a Model 3/Y if you have allergies or are concerned about the cleanliness of cabin air in your vehicle.

With that said, if you’re looking to snag an amazing deal on a used Tesla Model S or Model X with Bioweapon Defense Mode, be sure to check out our used Tesla listings to find the exact Tesla you want!

We’ve also built an insanely good search function into Find My Electric, and listed Bioweapon Defense Mode as a configurable option on all listings, so it’s easy to search for Teslas that have it—so don’t forget to check that out and find the Tesla you’ve been dreaming of!