I suppose the same should apply to hybrid cars, which outnumber pure EVs significantly [1]. The effect comes from converting the kinetic energy back to the battery charge via generation instead of wasting it via friction, which is the whole point of hybrids.
For DIY EV conversions (I built some cars) you usually hook up the "regenerate braking" to the brakelight switch.
So as soon as you tap the brake pedal just a little, you start regenerating and see the amps flow back into the battery (I have a little display on my dashboard). Only when you press the pedal further, do you start engaging the friction brakes.
I have no statistics on brake pad differences because we didn't build enough cars/didn't cover enough mileage to measure, but it is obvious that you would cut down on brake pad usage.
Everything I know about EVs and the tech behind it I share on: youtube.com/@foxev-content
In four years of plug-in hybrid ownership, and maybe 50k miles, I haven’t even had to replace pads, and the car wasn’t new when I bought it. I even commented on the longevity at the dealership the last time I took it for a service, and they said they see it a lot with hybrids. The regen braking really does make a huge difference.
From what I've heard there's a countervailing effect for EVs, though - they end up generating more particulate pollution from tire wear because of greater vehicle weight and greater torque.
The number that I've seen bandied about is ~20% greater tire wear.
A well known fact by Brembo, one of the biggest brakes producers in the world, which has been working for years to find new products and new markets, preparing for the time when a lot more EVs will be on the road.
This is cool. I have a VW EV and use the B-mode for the "gas" pedal. It it not full one-pedal driving but IIUC exclusively uses regen. You can't decelerate rapidly, but most driving can be accomplished without touching the brake pedal except when down to a walking pace, where thanks to that square law relationship of speed to kinetic energy there's hardly any energy left to recover anyhow.
After a bit you learn how much you can slow down with it and (for me at least) it becomes a bit of a game to see if you can avoid using the mechanical brakes by choosing early enough to lift your foot.
As a result, the mechanical brakes get squeezed on every trip, but nearly all uses are during low speed maneuvering. If a light changes at the last moment or someone pulls out in front of me I will then have to make a substantial use of the mechanical brakes but that doesn't happen on every trip.
I never have to ride the brakes down a long hill, and it was really satisfying the one time I went down a hill long enough to see the battery state of charge increase by a percent or two.
How does brake dust compare to tire dust in terms of quantity? My understanding was that most of the black soot that accumulates near roadways is mostly tire particulate.
You can get similar results with proper deceleration, engine braking and downshifting. I’ve had brake pads last 110k miles (with room for 20k+ more), even though I lived in moderate hilly area. That’s probably 1/3 the brake dust, and comparable to an EV .
If you are getting lower MPG than the EPA rating, you are also burning up your brakes from heavy deceleration. Improve your MPG to 15% over EPA and your brakes will last a lot longer.
Also their studies were in European markets with tiny EVs and low speeds. Americans are favoring 7k-9k lb EVs (Hummer, Rivian), with massive brake rotors and PADs— at highway speeds 75mph+. A good driver of a 3k lb vehicle will produce less brake dust than a typical driver of a 9k EV.
Studies like this are helpful, but they are not comprehensive. Similar to the marketing that home LEDs would have 10-20 year longevity, yet in practice they burn out after a few years. The full supply and application chain has to align for the ideal results in practice.
> The EIT Urban Mobility report also refers to the bigger picture: moving commuters out of private cars and into public transport, cycling, or walking can achieve up to five times more reduction in non-exhaust emissions than individual electrification.
And this is just one the many nuisances produce by cars.
Electric cars do not massively reduce almost any of the pollution produced by cars.
We have to reduce the automobile fleet by at least 95% to solve all the nuisances produces by cars.
the brake needs a brand new design for EV... as of now it's used so little I kind of fear when I need it it's not going to be performant.
It's not simply not engineered for current EV use case where it's touched every once in a while, I think it can go weeks without being used.
However manufacturers don't have any incentive to blend it with regen from time to time, as to get it up to temperature requires a LOT of braking, which reduces the mileage/efficiency.
Even Volvo recently had a recall[1] over regen braking bug, it looks like brake-by-wire system where software have control over blending brake, and decides in this case to not engage physical brakes at all even when user input suggests more braking.
We just need a new brake system that can stay performant without being used at all for a long time and won't rust or jam
[1] https://www.caranddriver.com/news/a65464238/volvo-brake-fail...
> The health effect is especially critical for urban disadvantaged groups, where exposure to partical matter has been shown to be related to increased asthma rates, cardiovascular disease, and other respiratory conditions.
Why would the health effect be more critical for disadvantaged groups than for other urban groups?
> alluding to the black discolorations on alloy wheels
There are ceramic brakes that produce very little particulate matter by comparison to semi-metallic. The only downside is performance can degrade more in extreme driving conditions (sustained racing with heavy braking). For a daily driver, it's a quieter and cleaner material.
Very urban focused of course given the site and there's nothing wrong with an urban focus for EVs.
EVs as they are being pushed on us are made for cities. Outside of a dense urban area, EVs without a gas/diesel powered charger (aka hybrid) are much less useful, but I do not want to see charging stations everywhere either.
Kinetic recovery is great, but as there are orders of magnitude less braking required driving outside of cities, the recovered energy is also much less, and the brake dust generated is also much less. Also there are far fewer cars per mile of road (let alone size of the area) and any brake dust pollution is spread over a much wider area.
Many of the negative pollution issues associated with cars are due to excessive density in urban areas, the added amount of braking, the added idling, and the extra acceleration repeatedly required in a city with a stop light every block.
Ban the stop and go hell of rush hour. Cars rolling at freeway speed without stopping pollute way less than drivers stuck behind idiots who can't just go forward down the road at the speed limit.
The human suffering and ecological impact reduced if only there would be a focus on enforcing speed minimums...
My DIY e-bike has regenerate braking. It makes no meaningful difference for the battery charge. But in terms of brake pad life, they do seem to last about twice as long as before.
On a meta note, I come to HN for the typically more informed and sometimes expert takes on the issues and articles that surface here, especially for tech related news. It's interesting how even this site is not insulated from some absolutely insane misinformation about EV's that starts to show up in the comments whenever they are brought up. I mean, just look at how many comments this article about brake dust has generated.
Brake pads are small parts that last for years. It is nothing compared to the number of tankfuls of gas that an ICE car goes through over the lifetime of its brakes.
This is like the March of Dimes syndrome. We got rid of exhaust with electric cars, but the cars-are-bad activists continue to exist and need something to gripe about.
I dream of a future where societes manage to price in all externalities into the objects they produce. This of course requires us to be(come) more honest about the hidden costs to society each and every objects and its usage brings with itself.
What we do with that knowledge is another question, but right now my feeling is a lot of bad actors skew the picture to make themselves look good while regular people are left to breath the dust.
I went to get new tires on my truck last month. 3 of the 5 bays at the tire shop had teslas getting new shoes. I asked the shop owner and he said EVs eat tires. Like 9-12 months max lifespan, great for business. I couldn't believe it but I've always heard there's exponential wear on tires relative to weight.
Has anyone modeled how much excess cement and asphalt pollution is generated by having a tiny car weigh as much as a giant truck? Or the water usage of increased lithium mining?
EVs are like an inferior product being shoved down everyone's throat when consumer cars don't even account for the most emissions globally.
> Gains, however, are not equitable. Low-income neighborhoods, which often endure the highest pollution impacts, have seen slower EV uptake, demonstrating the necessity of access to clean transport on an equitable basis.
Air quality tier list:
S-tier: African/American/Australasian countries that were never discovered by the West, and have no energy sources (hypothetical)
B-tier: Western countries and similar (e.g. Japan), and those who've had a resource that they've traded for Western advances (e.g. Asia/Middle East) that can afford nuclear and renewables
D-tier: Sub-Saharan African/South American countries that now have energy needs but are burning coal or diesel to meet them
Electric cars produce less brake dust pollution than combustion-engine cars
(modernengineeringmarvels.com)514 points by tzs 24 July 2025 | 751 comments
Comments
[1]: https://www.consumeraffairs.com/automotive/how-many-electric...
So as soon as you tap the brake pedal just a little, you start regenerating and see the amps flow back into the battery (I have a little display on my dashboard). Only when you press the pedal further, do you start engaging the friction brakes.
I have no statistics on brake pad differences because we didn't build enough cars/didn't cover enough mileage to measure, but it is obvious that you would cut down on brake pad usage.
Everything I know about EVs and the tech behind it I share on: youtube.com/@foxev-content
Zero tailpipe emissions, drastically removed brake dust, slightly higher tire wear (due to weight), but much better overall than ICE.
The number that I've seen bandied about is ~20% greater tire wear.
After a bit you learn how much you can slow down with it and (for me at least) it becomes a bit of a game to see if you can avoid using the mechanical brakes by choosing early enough to lift your foot.
As a result, the mechanical brakes get squeezed on every trip, but nearly all uses are during low speed maneuvering. If a light changes at the last moment or someone pulls out in front of me I will then have to make a substantial use of the mechanical brakes but that doesn't happen on every trip.
I never have to ride the brakes down a long hill, and it was really satisfying the one time I went down a hill long enough to see the battery state of charge increase by a percent or two.
If you are getting lower MPG than the EPA rating, you are also burning up your brakes from heavy deceleration. Improve your MPG to 15% over EPA and your brakes will last a lot longer.
Also their studies were in European markets with tiny EVs and low speeds. Americans are favoring 7k-9k lb EVs (Hummer, Rivian), with massive brake rotors and PADs— at highway speeds 75mph+. A good driver of a 3k lb vehicle will produce less brake dust than a typical driver of a 9k EV.
Studies like this are helpful, but they are not comprehensive. Similar to the marketing that home LEDs would have 10-20 year longevity, yet in practice they burn out after a few years. The full supply and application chain has to align for the ideal results in practice.
And this is just one the many nuisances produce by cars.
Electric cars do not massively reduce almost any of the pollution produced by cars.
We have to reduce the automobile fleet by at least 95% to solve all the nuisances produces by cars.
58 days ago: "Another way electric cars clean the air: study says brake dust reduced by 83%" (103 points | 184 comments): https://news.ycombinator.com/item?id=44113256
There are ceramic brakes that produce very little particulate matter by comparison to semi-metallic. The only downside is performance can degrade more in extreme driving conditions (sustained racing with heavy braking). For a daily driver, it's a quieter and cleaner material.
EVs as they are being pushed on us are made for cities. Outside of a dense urban area, EVs without a gas/diesel powered charger (aka hybrid) are much less useful, but I do not want to see charging stations everywhere either.
Kinetic recovery is great, but as there are orders of magnitude less braking required driving outside of cities, the recovered energy is also much less, and the brake dust generated is also much less. Also there are far fewer cars per mile of road (let alone size of the area) and any brake dust pollution is spread over a much wider area.
Many of the negative pollution issues associated with cars are due to excessive density in urban areas, the added amount of braking, the added idling, and the extra acceleration repeatedly required in a city with a stop light every block.
The human suffering and ecological impact reduced if only there would be a focus on enforcing speed minimums...
This is like the March of Dimes syndrome. We got rid of exhaust with electric cars, but the cars-are-bad activists continue to exist and need something to gripe about.
I always use the cruise control to decelerate and accelerate. Anyone else has that habit?
I’m not sure how you get more tire wear but less brake dust.
I've owned a Pirus (hybrid), Camry Hybrid and now a Rav4 Hybrid plus a MG4 EV.
The rav and MG4 are too new to count, but the other two I owned for about 10-13 years each.. we NEVER needed to change the brake pads.
Not once.
If you're having to change the brake pads on a car like this, you're a leadfoot with no core strength issues :-P
What we do with that knowledge is another question, but right now my feeling is a lot of bad actors skew the picture to make themselves look good while regular people are left to breath the dust.
I think it would have radically improved air-quality around roads and highways
Every runner and cyclist would have greatly appreciated it
Tyre wear isn't that important to me.
EVs are like an inferior product being shoved down everyone's throat when consumer cars don't even account for the most emissions globally.
Air quality tier list:
S-tier: African/American/Australasian countries that were never discovered by the West, and have no energy sources (hypothetical)
B-tier: Western countries and similar (e.g. Japan), and those who've had a resource that they've traded for Western advances (e.g. Asia/Middle East) that can afford nuclear and renewables
D-tier: Sub-Saharan African/South American countries that now have energy needs but are burning coal or diesel to meet them