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It seems that there has been fundamental mistakes and overstatements in the amount of particles from brakes in much of the secondary research in the last decades.

Details: https://pubs.acs.org/doi/10.1021/acs.estlett.4c00792



One would also expect that EVs wouldn't emit that many particles from brakes since the brakes typically wear much more slowly than with ICE cars.


But they are heavier. Not saying it offsets the effect but it's just not straight forward to assume either way.


EVs have very low brake wear because you simply aren’t using the friction brakes at all most of the time.

A lot of EVs even have smart “blended” brake pedals that preferentially apply regen braking when you press the pedal. Only in particularly hard stops will the friction brakes get used.

An easy way to test/observe this is simply to check for wear on the brake pads of EVs compared to combustion vehicles of similar mileage.

Tires, on the other hand, do tend to wear out quicker in an EV. Partly due to weight and also due to higher performance/acceleration compared to combustion models.


This little friction break usage is actually something which manufacture need to consider. They need to activate once in a while to stop rust and other problems.


They almost certainly do. For example, our Chevy Volt (EV + gasoline engine range booster) puts the engine through a maintenance phase if you haven’t used the engine in a few weeks, and will force the engine to consume any fuel left in the tank if it hasn’t been refilled in several months.


We're talking about brakes, not engines.

But I know at least one EV maker that has a manually selected mode that guides you through driving with the brakes engaged for surface treatment, as rust buildup will be the main issue.


In the US, the average car weight and the average EV weight are basically identical. (4300 pounds vs 4400 pounds). When you compare similarly sized models the EV tends to be about 10% heavier, but gasoline cars tend to be larger than EV's.


In the EU an average car is 1400 kg (3000 lbs), with most vehicles probably in the 1000-1200 kg range. We don't really want the average here, but the median - and we don't want to compare to the average EV, but to the equivalent EV - comparing an F150 to, say, a model 3 isn't right.

A BYD Dolphin, roughly sized like a VW Polo, is some 400kg heavier than the polo. A Polestar 2 is roughly 500 kg heavier than equivalent sized cars. In other words, something like 33% heavier.


FWIW I learned semi recently that cars get heavier and heavier because it improves their “ecology” rating… the ratings consider that moving 50% more weight with only 33% more gas is better than moving 0% extra weight with 0% more gas. And so a heavier car that uses a little more gas gets a better energy rating.

It’s moronic. But that’s how it works and why cars are getting bigger and bigger.


BYD Dolphin is size of Golf not Polo.

BYD Dolphin weight 1600kg, length 4290mm.

VW Polo weight 1580kg, length 3971 mm.

https://www.automobiledimension.com/model/byd/dolphin

https://auto.economictimes.indiatimes.com/cars/volkswagen-po...


You are comparing the max loaded weight of the polo with the unloaded weight of a dolphin.

VW Polo Mk6 is 1751mm wide, 1461mm tall, 4067mm long and has an unloaded curb weight of 1105 kg. https://en.m.wikipedia.org/wiki/Volkswagen_Polo_Mk6

The BYD Dolphin 2025 60kWh is 1770mm wide, 1570mm tall, 4290mm long, and has an unloaded curb weight of 1658 kg. https://bydautomotive.com.au/brochures/BYD-DOLPHIN-2025.pdf.

The VW Golf Mk8 might be a better comparison with an unloaded curb weight of 1255 kg, which reduces the gap from 543kg to 403kg.

(Note that for the gasoline and diesel cars, lighter trims give longer range, whereas it is opposite for electric cars, and that a fully loaded 45L tank of a polo weighs less than 40kg, especially if gasoline)


There is a 200kg difference between lowest trims of Dolphin and Golf, while Dolphin is slightly bigger.

2025 BYD Dolphin, length 4290mm height 1570mm, curb weight 1506kg - 1658 kg

2025 VW Golf, length 4282 mm height 1483 mm, gasoline empty weight 1307 kg - 1492 kg

https://www.volkswagen.de/de/modelle/golf.html/__ui/technisc...


The lower battery trim is not available in all markets, and only does 300km on a charge which is below average. As such the minimum weight will have to be the 1658 kg value.

The BYD is taller to offset the battery, making the size misleading. However, the golf is not particularly a particularly good or space efficient car - others will do better at similar or lower weight.

250kg seems like a fair minimum weight increase, roughly 20%. The larger the car, the larger the gap though, as the rocket equation catches up - see a Skoda Octavia vs. a Polestar 2.

EVs are still way more efficient, but that doesn't mean we should turn our blind eye to making an already bad tire problem worse.


Higher trim Dolphin has 150kW motor and weights 1658 kg. VW Golf with 150 kW (204 PS) engine weights 1492 kg empty. I see only 10% difference.


Same tier EVs are always more powerful than gasoline cars as they are generally just battery limited, not motor limited.

EVs are just a better tech in that regard, and buyers are not buying a Dolphin or golf based on torque or max HP. They're compacts in the same space. Someone looking at a dolphin would more likely be looking at the lighter eco motors.

This is true in other tiers too, e.g. a performance tier gasoline car might be 250-350 HP, while the same tier EV might start at 450-550hp just because they can.

The difference within a tier, simply based on the fact you're replacing at best a lightweight 100kg engine with 400-500kg worth of battery, can't be as small as you suggest.

With larger EVs, the battery weight is much greater, increasing the impact. Rocket equation and all.


> You are comparing the max loaded weight of the polo with the unloaded weight of a dolphin.

In this context, what is the air speed velocity of an unloaded dolphin? Especially compared to an unladen swallow?


They're not inherently heavier. They're only heavier if you put a long-range battery in them, even then it's not by very much, and even that may not persist as higher energy density batteries are developed.

Or to put it another way, the difference between a small car and a large SUV is far greater than the difference between an electric car and a gasoline car.


A Tesla Model Y is 30% heavier than a Honda CRV. They have alot of other advantages, and are about the same weight as a three-row SUV and lighter than a Tahoe on a truck frame.

We shouldn’t be singling out EVs if we suddenly care about tire wear… it’s pretty ridiculous.


The lightest current Tesla Model Y is ~25% heavier than the lightest current Honda CR-V. The heaviest current Model Y is ~12% heavier than the heaviest current CR-V (hybrid). A Jeep Grand Wagoneer is ~280% heavier than a Nissan Versa.


Again, bike-shedding stats on EVs is a waste of time if you care about pollution from tire wear.

If we want to reduce particulate pollution, we’d have regulations to govern acceleration on EVs, make tire monitoring more annoying, and have manufacturers certify tires and make compliance required during state emissions inspections, and get aggressive about the motor carrier overweight enforcement.

If Tesla or other EVs have a problem here, it’s that they are putting inappropriate tires on the cars.


There’s a great deal possible that could reduce pollution that has nothing to do with tires. Outlawing non hybrid gas / diesel cars for example would be a significant step forward. As would favoring rail over big rig trucking etc.

Instead the topic is almost exclusively brought up as an attack without any real world studies supporting the ideas presented. Because actual studies show EV’s improve air quality over ICE engines.


I think we violently agree with respect to EVs… it’s just whataboutism.

But I do think tires are a significant environmental problem, especially in urban areas and when combined with diesel soot. We’re also poisoning soil by allowing shredded tires to be used as mulch, which is gross in many levels. Shredded tires are also used as aggregate for roads, so road wear also contributes to particulate pollution from tires.


Those are wildly different crossovers. That glass roof on the Y adds a lot of weight, it’s kind of silly how popular such an impractical feature became.

The other common issue with EV’s is many don’t integrate the batteries casing as a structural element. Skipping the lead acid battery would also be useful, but that’s a different issue.


Size for size they’re heavier. Maybe someday not but they are.


But the fact that EV brakes don't wear at nearly the same rate as ICE brakes still stands.

My EV6 (pretty heavy car) manual explicitly says "you should probably do some hard breaking from moderate speed to prevent corrosion on the brake discs".

Because 90+% of the time when you press the brake pedal the friction brakes aren't being used at all, it's all regen.


The Standard Range model 3 weighs 3,582 lbs, while the Long Range and Performance trims both weigh 4,065 lbs.

The BMW 3 Series has a curb weight ranging from 3,536 to 4,180 pounds


Drives me up the wall that medium sedans curb in the same ballpark as fullsize trucks from the 70s and 80s.


It's true they are not that much heavier in terms of pure numbers. But road wear is a proportional to the difference in axle weight to the fourth power.


But this also means that almost all of the wear is from trucks.

This whole meme comes from junk science (https://www.emissionsanalytics.com/news/pollution-tyre-wear-...)

> we found that the car emitted 5.8 grams per kilometer of particles. Compared with regulated exhaust emission limits of 4.5 milligrams per kilometer, the completely unregulated tyre wear emission is higher by a factor of over 1,000.

They took plastic shedded by a gas car on non-EV tires, and compared it by weight to safety limits for gaseous emissions. This makes as much sense as saying that a lump of coal has 1,000 times more carbon than the safety limits for carbon monoxide.


That doesn't pass a sniff test; emitting 5 grams of tyre rubber per kilometer, a 12Kg tyre would be completely vanished in 3000km but really they can last 60,000km with only the tread worn down beyond safe levels and the bulk of the tyre still there.


Looks like mg was changed to a g, though I'd suggest even then the estimate is too high (but probably to the correct order of magnitude).


What meme? The article you linked talks about tire wear. Not road wear. I didn't even touch on tire wear. Road wear is well studied. https://en.wikipedia.org/wiki/Fourth_power_law

I really can't place your comment, you simply start talking about something completely unrelated to what I was talking about.


It doesn't matter though? Less braking material used equals less particles emitted. So if we accept that brakes on EVs last longer (and are otherwise similar in size), then they pollute less.


My Volvo XC60 T8 is not even a full EV but after 5 years of ownership the brakes on this 2200kg, 400bhp SUV are only 10% worn - it's all thanks to regenerative braking with the EV motor. It definitely makes a massive impact on how quickly the brakes wear out(as in - much much much less than in a normal car).


But the brakes don't get used 90% of the time,it's all regen.


The pads aren't any bigger. If they last longer then they're emitting less.


If you want to go into the details of this, for all the things people hve mentioned, you have to calculate the road wear done by trucks carrying fuels to stations every day. Electricity does not need the same regular road wear as ICE vehicles do.


Yeah, the refining and transport of petroleum products always gets left out when talking about EV pollution.

It's pretty energy intensive to separate crude oil into it's various parts.


Sure. Because windmills and photovoltaics grow naturally from seeds. You need quite a bit of an equipment to put up one windmill. They are usually built in some distance from an existing road. So you need special service roads. Those need to be wide and take heavy load because the equipment like cranes need space and are themselves heavy. Then you need special transport because main components like propellers are oversize load. Then you need to transport them hundreds for kilometres…, and then you need the rest of the infrastructure to distribute generated electricity. Yes, let’s compare apples to apples.


Yes and what's the service life for that windmill or solar panel? What's the service life of the distribution system?

And what was the cost to build out and constantly repair the refinery?

The problem you have with your talking points is that solar and wind both have decades of service in them whereas fossil fuels are single use product. Further, once the infrastructure is created large portions of it can be reused when solar and wind hit their end of life. You only need new lines and roads for new installations.

All energy collection will have some environmental impact. It just so happens that fossil fuels have an outsized impact for the energy they create.


Oh yes, the refinery. Fortunately some of that oil and gasoline can be used in various stages for renewables.


For sure, it's a matter of degree.

I'm not an absolutist about crude oil. It'll likely have a place in society for a long time.

With that said, it's a matter of degree and where it should be deployed.

If, for example, burning 1 gallon of gas sets up a power generation which produces the equivalent of 20 gallons of gas without emissions, that's a worthy trade off.

As it turns out, that's roughly the energy trade-off for new solar/wind installations assuming a pure fossil fuel grid.

What you are saying isn't a gotcha. The entire cycle of CO2 released for fossil fuel use is not comparable to the CO2 released installing renewables. That some is released is meaningless.


It is in fact straightforward to assume EVs create way, way less brake dust, because of how much less often they need brake replacements than ICE vehicles with the exact same brakes.


Then from what the pollution in the subway come from ?


most subway trains are decades old - newer fleets have regenerative braking[1]

But also ... almost a century of brake dust because nobody is going through and vacuuming the tunnels.

[1] https://tfl.gov.uk/corporate/transparency/freedom-of-informa...


Interesting. Looks like it the line isn't able to take the energy (I'm guessing voltage is already too high) they dump the energy into a resistive heater.

Makes sense, it's just going to be heat anyways. I wonder how often that happens vs the energy getting dumped into the line.


Depends on where you live. There is barely any pollution in Prague metro.


Greens seem to deceive in the same way as green-washing except with greener deceptions (whereas green-washing is capitalists pretending to be green).

Example: a report on the cost-benefit of using bicycles, that comes out with a fantastic positive number for introducing a cycle lane. Except the number depends on a monetary estimate of the benefits to society for health improvements. I'm sure the health improvements exist, and it wouldn't surprise me that the health benefits to society were well estimated. The problem is that by cherry-picking benefits you can simply ignore all monetary benefits of cars (no benefits for cars were mentioned as I recall).

I've seen it in other articles which talk sacharrinely about the benefit of some green tech. But ignoring real costs and certainly not being balanced. The ultra-idealistic greenies are not helping their cause when rubbish is repeated.


It would be great if you could cite the report you're talking about, so we can judge for ourselves whether you're steel-manning or straw-manning its methodology.


I found it:

https://economics.acadiau.ca/tl_files/sites/economics/resour...

" Thesis submitted in partial fulfillment of the requirements for the Degree of Bachelor of Arts with Honours in Economics Acadia University, 2013" biased and poorly balanced.

  As far as can be determined, no cost-benefit analyses of bicycle facilities have been carried out for locations in Canada.
Maybe says more about the searching skills author than the state of cost-benefit analysis in Canada - but it sounds bad.

  The daily benefits from one person switching from car travel to bicycle travel for commuting are estimated to be $2.14.
Most of that 2.14 "savings" is car ownership and maintenance costs, which is bullshit because they say elsewhere you need a car for the days your can't cycle. Nice double counting eh?

Plus the internal+external "health ben." added up to be about equal to vehicle ownership costs.

See the "analysis" bias?

Perhaps an Acadia University Honours in Economics is toilet paper.


Dude someone did this for a check box. It’s honestly more shocking that you read it


> "example: a report on the cost-benefit of using bicycles, that comes out with a fantastic positive number for introducing a cycle lane."

Rubber-stamp a multi-billion dollar highway widening project that won't reduce traffic*, no problem, doesn't deserve any comment. Bike lane? Scrutiny with a fine-tooth comb, subject it to years of studies, complain about the cost, complain about why anyone would want a bike lane - they must be up to something! The slider is jammed 98% over towards 'cars' and still the car drivers are like "Won't someone PLEASE think about the cars?!".

"No benefits for cars were mentioned as I recall" - seriously, you think everyone might have forgotten that cars exist in the twenty seconds between when they last saw one, or heard one, or had to wait to cross a road, or used one, or heard someone talk about one, or saw an advert for one? A study on bike benefits didn't say that cars were great, do you want a study on wheelchair accessibility to talk about the benefits of being able bodied?

> "I'm sure the health improvements exist, and it wouldn't surprise me that the health benefits to society were well estimated"

"Worldwide, we estimate that physical inactivity causes 6% (ranging from 3·2% in southeast Asia to 7·8% in the eastern Mediterranean region) of the burden of disease from coronary heart disease, 7% (3·9–9·6) of type 2 diabetes, 10% (5·6–14·1) of breast cancer, and 10% (5·7–13·8) of colon cancer. Inactivity causes 9% (range 5·1–12·5) of premature mortality, or more than 5·3 million of the 57 million deaths that occurred worldwide in 2008. If inactivity were not eliminated, but decreased instead by 10% or 25%, more than 533 000 and more than 1·3 million deaths, respectively, could be averted every year." - https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

*roads are wider than they used to be; if adding lanes reduced traffic, there wouldn't be any traffic these days.


Yeah: I'm totally not a fan of biased car shit either. Some of your examples seem like strawmen to me.

> complain about the cost

Bike lanes in my country are mostly paid for by taxes on cars and petrol. The costs/benefits are often justified by cherry-picked benefits (e.g. reduced car congestion, or reduced pollution). The congestion arguments anecdotally appear to be lies: low usage priority cycle lanes seem to cause extra congestion (through phasing of lights and islands and other traffic controlling features).

Try and fairly point out that the numbers are juggled and you'll get skewered by cyclist ideologues. Read my sister comment where I reference the thesis that was the basis for my original comment.

I have an acquaintance working in our council on improving bike lanes.

I'm not against bikes. I'm against badly biased reports : towards/against both cyclists or cars.

Balanced discussion seems so difficult.


The benefits of getting more of the population to cycle are so beneficial that it's a joke to even try comparing the return on investment of cycle lanes versus car infrastructure and of course, when there's lots of cars, it pretty much pushes out other forms of transport due to the size/weight/danger/pollution of the cars.

Here's a somewhat biased look at the economics of cycling:

https://www.cyclinguk.org/briefing/case-cycling-economy


> "Bike lanes in my country are mostly paid for by taxes on cars and petrol"

Governments get money in, and they spend money. There's no real sense in which "bike lanes are paid for by petrol taxes", nobody can prove it either way by measuring anything - that's a matter of where they write the numbers in a spreadsheet - it's not the same money, as long as all of it balances. It's an arbitrary accounting choice and you're choosing to raise it as a talking point because it makes car drivers mad, not because it has real world consequences.

> "The costs/benefits are often justified by cherry-picked benefits (e.g. reduced car congestion, or reduced pollution)."

The fact that you default to "the current level of car pollution with tens of millions of cars everywhere is the default" is a bias. That you think "reducing pollution" is cherry picking is a car-bias. That people have to argue for being able to breathe without getting lung cancer as a "nice to have" against a default of cars-for-everything is a massive bias.

> "The congestion arguments anecdotally appear to be lies: low usage priority cycle lanes seem to cause extra congestion (through phasing of lights and islands and other traffic controlling features)."

Public transport (which I will include bike lanes, pavements, sidewalks, L-trains) need to go from where people are, to where people want to go. It's a very car-biased talking point that a city put a bike lane from nowhere to nowhere, and look! The cars are inconvenienced and hardly anybody is using the bikelane, so bike lanes must be the problem, get rid of it. You can't just slap a bike lane in London, decide nobody is using it, and get rid of it. You need enough bike lanes that people can get from where they are, to where they want to go, safely - feeling safe, well lit, clear of mud and snow and muggers and not along a main road - and enough of those safe journeys for long enough that people can change their behaviour. Several rounds of New Year's Resolutions to get fit, months of seeing family and coworkers gradually cycling, increasing numbers of cyclists (or walkers) normalising it, seeing "normal people like me" bringing a bike to work or to the shops not just lycra clad idealists - for large numbers of people to move from car to (foot/bike/bus/tram). Amsterdam started changing towards encouraging cycling in the 1970s and it didn't get a reputation as a bike city for decades. Cars have a hundred and twenty years of being entrenched, multiple generations of people who think cycling is for children and the roads are too dangerous to cycle (they are!) which needs pushing back against.

> "Try and fairly point out that the numbers are juggled and you'll get skewered by cyclist ideologues."

I don't know if you can justify "existing without breathing car exhaust" in economic terms. I don't think one should have to. I don't think one should justify bike lanes in terms of reducing traffic congestion - moving people around effectively needs city planning overviews, zoning changes, joined up public transport where the schedules line up, until it overall becomes convenient to move around without driving. Bike lanes and cycling can be part of it, but you can't justify one bike lane or project in terms of reducing congestion. If one demands that bike lanes be justified in the framework of "good for car drivers" and then rejects the numbers because they've been juggled to fit in terms of "good for car drivers" when that really isn't the point at all, that's not balanced or unbiased.

> "I'm not against bikes. I'm against badly biased reports : towards/against both cyclists or cars."

It's just convenient that dismissing badly biased reports towards bikes means nothing changes, and dismissing badly biased reports in favour of cars means nothing changes, and that continues car dominance, which is nice.

Even starting the sentence "I'm not against bikes" is a bias. Cars parked up and down both sides of every side-road. Solid slow moving car traffic for multiple hours in the morning and evening every weekday. Billions spent on multi-lane motorways moving massive cars with a single person in them. Young drivers revving the bollocks off their engines at midnight, motorbike riders with exhaust volume increasers, pollution, road accidents, burden of cost on car owners, and you start with "I'm not against bikes". It's the millionaire saying "I'm not against helping the homeless, I just don't like the way they're asking for help. I'm just being unbiased and fair".

> "Balanced discussion seems so difficult."

It isn't a balanced world, it's a car-dependent, car-dominated, world, deliberately, by car advertising, governments subsidising car manufacturing, car company lobbying, car company bribing, and capitalism framing everything in terms of profit and having nothing in terms of community, quality of life, wellbeing, welfare, health. It's not an accident that the available land has been dedicated to cars, and that makes cars very convenient. It isn't because cars are inherently convenient it's that we have spent unthinkable amounts of effort carving through hills, flattening rocks, stabilising mud, to make cars convenient. Because cars are expensive so it's good for car companies if lots of people buy them. One can't take an unbiased "fair" position, one must make choices - one can't sit on the fence between "it's important that people can get to home/social/work/shops in many ways" and "it's fine if cars are the only way and if that's a problem for some, tough".




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