Another way electric cars clean the air: study says brake dust reduced by 83%

by xbmcuseron 5/28/2025, 6:40 AMwith 181 comments

by ChiefNotAClueon 5/28/2025, 6:56 AM

To those wondering about tire wear:

"Despite the slightly higher levels of tire wear from EVs, brake dust was found to be more unhealthy, as brake dust is much more likely to become airborne (>40%) than tire wear is (1-5%). So EVs create a lot less of the worse thing, and a little more of the less-bad thing."

by Tade0on 5/28/2025, 7:27 AM

Audi had an interesting proposition regarding making electric cars actually clean the air as opposed to just avoiding emissions:

https://www.audi-mediacenter.com/en/press-releases/audi-urba...

ICE cars already do that in a way, as they suck a significant amount of air through their intake filters (CADR = displacement x RPM).

Audi's filter was supposed to have been more fine-grained to catch brake dust and tire particles, but sufficient legislation never materialized, so the project was shelved.

by merekon 5/28/2025, 6:59 AM

> It turns out that BEVs (battery electric vehicles) reduce the amount of brake dust by 83%, according to a new analysis by EIT Urban Mobility (a body of the European Union) and Transport for London. The study looked primarily at London, Milan and Barcelona.

> The primary reason for this is the use of regenerative braking, meaning that electric vehicles can slow down without rubbing friction brakes. Other vehicles that use regenerative braking reduced brake emissions too, with Hybrids reducing them by 10-48%, and PHEVs by 66%.

Technically not cleaning the air as the title says, but still a major improvement.

by epistasison 5/28/2025, 6:55 AM

Brake dust is such nasty stuff, yet we place schools and homes right next to the rivers of pollution that we call highways. I'm hopeful that we will legalize the building of less car-dependent housing, but until then at least EVs will help.

by atoavon 5/28/2025, 7:47 AM

I was living on the 4th floor next to a main road once. I could wipe a thick layer of gray dust from my balcony furniture eevery two days. This surprised me initially, since it was high up and a big garden separated the road and the house.

The worst thing was the noise. When I lived there I tuned it out, but when I slept for the first night in my new flat it felt like someone lifted a huge rock from my chest.

Cars in cities are a really thing to tolerate from the standpoint of people who bear the cost of them being there, EVs help reducing two of the main issues with cars. Issues like space use remain (housing prices skyrocket while there is a ton of empty space used for storing cars while nobody drives). Who knows, maybe EVs can solve this one too one day.

by cyberaxon 5/28/2025, 7:43 AM

Anybody who ever driven an EV, would have told that the initial scare about brake dust was pure nonsense.

EVs barely use frictional brakes, with regen performing most of the braking action. Frictional brakes only really come into play to slow down from around ~5 mph to a complete stop.

And even that can be eliminated by essentially running the motor backwards, at low torque. This mode of braking is sometimes used on train engines as an emergency braking method.

by Animatson 5/28/2025, 8:04 AM

Works for modern trains, too. I was watching one of the new electric CALTRAIN multiple units pull into a station. The motors did all the braking except for the last few feet of stopping. The friction brakes normally go on below 5 MPH, and are rather noisy for disk brakes. Emergency braking is friction brakes only.

by matt3210on 5/28/2025, 7:58 AM

Are they “cleaning” or just not producing as much dirty? Semantics…

by freetonikon 5/28/2025, 9:45 AM

Many people complained when VW "dared" to use drum brakes in the rear of ID.3, but it's a good idea, I think. Drum brakes do not pollute (as much), are cheaper, and easier to maintain. In the front, there are still regular disk brakes, and together with regen (recuperation), the overall use of polluting disk brakes is minimized. I'd be curious to see how much brake dust pollution is produced on average in this setup, compared to a regular ICE car with 4 disk brakes and no regen.

by incomingpainon 5/28/2025, 11:15 AM

I drive completely in '1 pedal mode' which essentially lets regen do the braking for me. I maybe need to use actual brakes once every few days.

I would say something as well. The less noise from an EV changes people. They'll not look both ways when crossing a road and just walk out right in front of you.

by trklaussson 5/28/2025, 8:49 AM

As a driver of a diesel car: Sure thing. But driving style is what is behind this result.

With electric cars, your "engine" (motor) brakes for you. This is something that already happens in ICEs though: you can just let the car roll, don't drive in a rush etc.

However, everyone is in a rush: illegally overtaking, tailgating, honking... The conditions and social behavior on the road push for inefficiencies.

by teo_zeroon 5/28/2025, 11:57 AM

Is there an explanation why BEVs fare better than hybrids in terms of brake dust? They use the same principle, so I expected similar performances.

The article gives no clues, only these results:

> It turns out that BEVs reduce the amount of brake dust by 83% [...] Other vehicles that use regenerative braking reduced brake emissions too, with Hybrids reducing them by 10-48%, and PHEVs by 66%.

by bamboozledon 5/28/2025, 7:53 AM

Another way to say the same thing: Electric cars still pollute, just a bit less than regular cars.

by Pavilion2095on 5/28/2025, 7:25 AM

> As it has become more and more untenable for anti-EV propagandists to deny the air quality benefits of EVs, a common refrain from them has become “but tailpipe emissions aren’t everything, what about brakes and tires, huh?!”

What is this website? Tell me about the story, don't argue with imaginary haters and trolls. The writing is so poor there.

by ndsipa_pomuon 5/28/2025, 6:53 AM

I'm glad that they address the increased tyre wear pollution. I'm not entirely(!) convinced that EVs only have slightly increased wear as there seems to be plenty of reports of EVs going through tyres a lot quicker though estimates do seem to vary from about 30% to 50% more wear.

(Also great that the report mentions the importance of walking/cycling for city transport)