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Comment by t-writescode | Hacker News Reader

Two of the best parts, to me, about electric cars are:

1) lower pollution where people live, so you can go for runs and such without breathing in a bunch of noxious gas

2) how much quieter inner city walking will become. It can’t come fast enough!

Big improvements, but keep in mind that air and tyre resistance are the loudest aspects of driving at even moderate speeds.

And that pollution of tire degradation is one of the biggest sources of particles from cars

Don’t forget the brakes. When the rotors get worn down, where did they go?

Not a big issue with evs, most use regenerative breaking.

As do hybrids! Even mild hybrids like those new pickups

The rotors aren't the problem, the pads are. Rotors are just cast iron, and they wear very slowly compared to the pads.

Do you have a source for that claim? Typically I see breakdowns by chemical formula

For example,

https://www.theguardian.com/environment/2022/jun/03/car-tyre...

https://www.washingtonpost.com/climate-environment/2023/07/0...

This. People always underestimate how much noise rolling resistance of tyres plays in the sound profile of traffic. Electric cars are worse under 50mph, basically because they're heavier.

Electric cars start and accelerate noiselessly - both very common activities in the inner city driving.

The parent's point is that the engine isn't the largest contributor of noise. At low speeds the engine noise dominates, at "high" (meaning normal driving speeds) speeds the tire noise dominates.

Go listen to a highway and see if you can hear the engines over the wooshing.

Cars in cities rarely travel quickly, spending lot’s of time stopped at traffic lights right where people cross the street or stuck in traffic.

The squeal of a worn out brake pads is largely mitigated by regenerative breaks which increase brake lifespan.

There are a lot of highways in American inner cities.

Those are frequently Highways in name only. If people are doing 2-3 mph in stop and go traffic it might as well have stop lights. Thus the frequent use of bypasses so people on long trips can actually get someplace quickly even if the distance increases.

Interstate 5 in Seattle would like a word with you. The traffic noise on that road is paradoxically loudest when nobody is driving on it.

It’s 8PM on a Sunday, and it currently has some traffic issues.

The only paradox is it seems louder when the rest of the city quiets down.

Another reason to limit inner city traffic to 30 km/h to 40 km/h :)

A bit of an aside on this. The last 30 years or so have been amazing for cutting down engine noise levels. In trying to squeeze out ever last drop of efficiency they have also reduced the noise levels.

Nowadays the only times I really notice them is either when idling or something from before the 90's is driving past.

On residential vehicles. Commercial vehicles are still a nuisance.

The other day I noticed a queue of suspiciously quiet gas cars. One or two had start-stop systems.

(Hybrids of course all implement start-stop, and after 20 years of wild success are still underrated)

This is the point that makes all of the miserable noise pollution from modified cars so much more grating, knowing that whatever is making excess noise means potentially useful (in a performance sense) power is escaping as sound somewhere in their drivetrain, so insofar as their objective is to make their vehicles loud for the sake of loud, these people are achieving the opposite of what they're trying to signal they're achieving.

Efficiency and power are not equivalent. All you need to do is look at the most powerful (hp per liter) cars and the exhaust systems they use for proof.

The people were talking about are slapping shitty cat deleted straight pipe exhausts on what are typically engineered to be economy or family cars, or small displacement motorcycle engines. People who don't see the offensively selfish stupidity in tripling or quadrupling the noise output of their mode of transportation just to get an extra 10% power, if that.

They're not running million dollar F1 cars around closed environments dedicated to the purpose.

> Go listen to a highway and see if you can hear the engines over the wooshing.

I regularly walk a trail ~0.5mi from a highway and the main sound I notice is from straight piped WRX-esque cars gunning it.

An ICE engine is vastly louder stationary at a stoplight or stuck in heavy traffic. Both of which are is really common in cities.

Regenerative braking is also vastly quieter.

No they are not. Electric cars are notably quieter under 50 mph. They are notably quieter at all speeds really.

Over 30km/h road noise dominates and EVs generate similar noise to ice cars: https://www.toi.no/getfile.php/1340825/mmarkiv/Forside%20201...

I don’t think this is something that occurs to people. When I jog, i noticed pre-AirPods pro that I could listen to podcasts fine on the side street blocks that i normally run on, but once I hit the avenue (more traffic and 30-40 speed), it’s hard for me to hear without noise cancellation.

In Europe at least, where most (?) transmissions are still manual, you will still get way more noise from an ICE vehicle than an electric vehicle at low speed. This is my experience everywhere here in cities, on small roads, etc. This is largely caused by the fact that people tend to not drive in an optimal manner (i.e. using a low gear instead of a higher one).

Maybe inside of a regular electric car, but the worst noise pollution in cities comes from cars and motorcycles with modified exhaust and incessant honking. Cars are loud and that's a problem by itself, but a car with a bad driver is exponentially worse than one with a normal driver.

That’s one part, but the other massive part is noise from freeways and the baseline white noise from faster roads, where most of the noise comes from tires. EVs are not better (and typically worse since they’re heavier) — the only way to fix it is 1. No freeways in city centers. 2. Fewer cars. 3. Noise barriers. 4. Asphalt that reduces tire noise (uncommon in North American cities, where concrete is used to improve the lifespan).

I can’t use my balcony in a downtown city center because the baseline tire noise from the highway is so loud, and that’s without the obnoxious exhaust

Yup,Electric cars aren't quieter at all compared to movement I.C.E cars. Speeds need to be lowered to 35km/hr or lower.

In residential and downtown areas, the sound is going to be dominated by engine idling, pulling away, and low speed cruising. It's ridiculous to argue that electric motors aren't a massive improvement in all of these cases.

Must really depend on the speed, because the experience I have with ICE vs electric at Europe city speeds, electric vehicles seem practically silent.

Then you haven't heard electric cars running at low speed or put in reverse. Try to chill near any space where EVs frequent (like near a parking lot or train station with lots of traffic) and it's a constant source of artificial speaker noise:

WHIRR! WHINE! HUM! LOOK AT ME I'M ELECTRIC WITH A BIG SPEAKER! WHINE! WHIRR!

BING, BING, BING, BING, BING! LOOK OUT HERE I COME IN REVERSE! BING! (The Ioniq 5 is a particularly bad offender here ... the reversing bing can be heard multiple blocks away).

I wish EV auto-makers would turn the default warning noise levels their cars emit WAY THE FUCK DOWN because it's seriously annoying! I get not wanting to startle pedestrians, but you don't have to alert the entire neighborhood...

> I wish EV auto-makers would turn the default warning noise levels their cars emit WAY THE FUCK DOWN because it's seriously annoying! I get not wanting to startle pedestrians, but you don't have to alert the entire neighborhood...

I'm pretty sure this is a legal requirement not something the EV manufacturers are choosing to do. Although I guess this may vary by juristiction.

Well it can be both can't it.

Car makers, conceding that they have to incorporate some sort of non-startle noise if they're building an ev, decide to lean into it and pretty soon the pr and marketing departments are trying to come up with the most "distinctive" non-startle branding sound possible, and we're off to the juvenile arms race of noise making one-upsmanship again.

It's cause otherwise "EVs are silently running over kids becomes another "we need incandescent traffic lights because for a couple weeks in winter LEDs don't melt snow"

The legislation requiring this is silly, are there any studies at all which shows it reduces harm... I couldn't find any. It would seem safer for children, and the population as a whole, if they banned vehicles which don't provide adequate front visibility. Maybe even require sensors that will prevent the vehicle from moving from a stop if something is detected in front.

There are blind people, who cannot know if a car is present if it's completely silent.

There's a spectrum between completely silent and so noisy you can clearly hear it inside a house a hundred meters down the street.

I was part of a recent conversation about hijacking the speaker and making it play Ludacris - Move B** instead.

Most road noise and even pollution comes from tires, not a gas burning engine. I lived about a half mile from an xway once. You'd hear an occasional jake brake or loud motorcycle, but by far the most annoying thing was the constant whooshing noises of normal cars passing by.

The best car is actually no car. No EV, not just ICE means no noise or tire pollution.

As someone who bikes regularly, electric cars seem almost noisier than regular driving gas counter parts, I don't know if's because they're heavier or what, but when they're moving at regular traffic speeds, they are not remotely quiet.

Sometimes you can even feel bigger evs as vibration, they're like light duty trucks

I have been a proponent of electric cars but the way it has panned out has made me less enthusiastic. Really it is just about showing you have a six figure salary and nothing to do with being kind to the planet.

My new phrase is 'active travel' and this means walking, cycling or using a wheelchair. The opposite of 'active travel' is car dependency.

For the car dependent person, walking is something you do after driving to the car park in the beauty spot, to get the boots out the back of the car and do 'hiking' as a leisure exercise, to not actually do anything of purpose. Cycling is the same, a bicycle is just a toy for leisure, with a piece of polystyrene having to be worn on the head.

In the world of 'active travel' the walk is to the shops or to see a friend. It is the same with cycling, rather than pointlessly ride on a 'toy', it is a trip to work or the shops, a journey of purpose.

With 'active travel' there is community. You meet people old and new on the journeys you take and you can stop and talk. Car dependent people can honk their horns and wave, but that is quite primitive communication compared to saying hello. Just today I met someone on the canal towpath that is cycling coast to coast, having met him a couple of days ago too. It was great to see him again, and that was just one interaction on my journey. I had to get somewhere so I did not stop to talk for too long, but you just don't have those sorts of interactions if trapped in a tin box, electric or otherwise. Yes there might be cup holders, air conditioning and massaging heated seats, but I prefer the community aspect of 'active travel'.

When people go car dependent they take themselves out of being part of the community.

A huge part of this is noise levels. Sometimes I use turn by turn directions on my phone, and, if I am on towpaths, the volume of 'after 200 yards, turn right' is embarrassingly loud. Yet, if I have the same volume and I am on a normal road, I make wrong turns because the noise of cars, even at a low speed on quiet roads, is too loud for me to hear the turn by turn directions.

Only if spending hours on canal towpaths and former railway tracks turned into cycle paths so you realise how absurd the noise of car dependency is.

Another phrase is 'livable neighbourhoods' and the idea is to put active travel first so there is a return to community and health. Sadly, electric cars are a folly. I don't hate on them, I have just discovered 'active travel'.

Incidentally, 'active travel' depends on health, and that means either being young or eating for nutrition. You can't walk your way out of a bad diet, or cycle out of it. There is a whole lot we need to work out and electric cars, sadly, are not it, not even for people that live in the countryside, have a dozen kids and a job a hundred miles away.

I feel like too many "active travel" proponents live somewhere that's perpetually 65 and sunny.

Edit: I'm a bike commuter. I just like arriving at my destination unsoaked in sweat.

Exactly, like the Netherlands and Denmark…

That's their summer highs.

Visit Sweden in the winter sometime.

Visit St Louis in the summer sometime.

As an avid recreational cyclist, I would much rather be active on a bike in Sweden in the winter time, then in virtually anywhere in the USA's south east or southwest, and even in the northeast, during the summertime. I'll still do it because I like riding, but I would never want to have to ride anywhere for any exertion-inducing length of time outside of a purely recreational scenario. I will be completely soaked and that's awful for everybody involved.

I want to know where they get all their time from. I'm flat out rat racing and would love to have time to use like this!

The fact that you feel like you can't have human interaction or community unless you're walking somewhere sounds like a skill issue on your part.

I happily drive to join friends and family all over the place.

> I happily drive to join friends and family all over the place.

Except you don't.

If you did then you would not be so passive aggressive with your comment. There is no need for that little put down regarding a hypothetical 'skill issue'. Why say something condescending that you would not say to anyone else in real life? Oh, car dependency, the disease worse than a STD.

Incidentally, I don't even walk. I cycle everywhere. I have time to say hello to my neighbours and a smile for other road users, even if they are trapped in a tin box.

Meanwhile, you endanger your neighbours with toxic fumes, deafen them with noise, make the street dangerous for any pets they might have, make the street ugly with a rusty tin box and destroy their climate. You might have a fancy car but you are an example relic from the boomer past, shortening your healthspan with every mile you drive.

Rather than patronise those that see value in active travel, consider joining them. Enjoy physical activity that is not a dumb workout, and, be the inspiration for others that want a clean, green future rather than the vroom-vroom boomer life of anger.

Sorry, but most car pollution is from the tires/tyres, not the exhaust. Electric cars don't solve that, and may even make it worse because they're heavier.

https://www.theguardian.com/environment/2022/jun/03/car-tyre...

The parent was worried about "noxious gas", not rubber particles. Cars with an ICE have tires as well, unfortunately.

Tires are only about 25% natural rubber; the rest is synthetic rubber, heavy metals, plastics, and additives. These get emitted as fine particulates that stick around in the air. They may not technically be a gas, but we breathe it in just the same.

I very much doubt that heavy metals such as mercury or lead are used to make tyres. I've only ever heard of steel belted tyres.

It used to be that wheels were balanced with small lead weights, but the use of lead for this has been banned in pretty much every western country, and wasn't contributing to road dust even when they were allowed.

"Hundreds of other ingredients, including steel, fillers, and heavy metals — including copper, cadmium, lead, and zinc — make up the rest, many of them added to enhance performance, improve durability, and reduce the possibility of fires."

https://e360.yale.edu/features/tire-pollution-toxic-chemical...

They didn't reference a source, and the claim is rather outlandish.

Cadmium and Lead are both quite toxic, and I'd be absolutely shocked if any tyre company in the western world used either of them anywhere near their products, let alone mixed into the rubber, which is insane.

"Tire fragments soaked in solutions with pH ranging from 3 to 8 did not leach measurable amounts of cadmium over a period of six week" from: https://www.echocommunity.org/en/resources/b1d9d1eb-afcb-472...

"Cadmium and lead concentrations were negligible." from: https://pubmed.ncbi.nlm.nih.gov/9085433/

"The low cadmium levels in their tyres was due to the efficacy of the zinc oxide purification process. In the nearly 50 years since the David and Williams study, Zn, S, and Cd refining has improved and this may contribute to low levels of cadmium being detected" from: https://www.sciencedirect.com/science/article/pii/S016041202...

So... it looks like tyres contain some Zinc, which many decades ago wasn't purified very well, which resulted in Cadmium and Lead being included as impurities in the Zinc. The industrial processes have improved and this is no longer a problem, but people are quoting tyre compound issues from the 1950s like they're still issues today.

Whoever wrote the article you linked couldn't be bothered to run a quick Google search to see if the problem still exists. That's unfathomably lazy.

PS: Not to mention that the lead added to fuel was a vastly bigger problem than any trace lead impurities that got into tyres.

Your link does not say what you purport it to say. It limits things to particle pollution. It makes sense that tires will create more particle pollution, but gasoline creates a lot of gas pollution as well.

The tire & brake particulates go into the air. Sure, technically not gas, but we breathe it in just the same.

Straw man. You said “most car pollution is from the tires/tyres.” That is unsubstantiated by your source.

This is not some secret:

https://e360.yale.edu/features/tire-pollution-toxic-chemical....

Interesting. This article you linked states that tires emit not only more particulate emissions than tailpipes during driving, but also more VOC emissions!

> Another area of research centers on the impacts of aromatic hydrocarbons — including benzene and naphthalene — off-gassed by synthetic rubber or emitted when discarded tires are burned in incinerators for energy recovery. Even at low concentrations, these compounds are toxic to humans. They also react with sunlight to form ozone, or ground-level smog, which causes respiratory harm. “We have shown that the amount of off-gassing volatile organic compounds is 100 times greater than that coming out of a modern tailpipe,” said Molden. “This is from the tire just sitting there.”

I'm starting to see more and more homes in the area where I live, Southern California in the LA region, switching from green unsustainable lawns to some form of hardscape/ xeriscaping.

one of the rising trends is the use of old tires as a ground cover source. These have been shredded and processed with a small amount of coloring into something that very strikingly resembles and spreads like wood chips until you pick them up and feel them in your hands.

Of course it better solution would be to not have tires that are so toxic to begin with, but there are very few products into which the most unusable kinds of recyclable plastic streams can be fed, and tires are one of them.

Certainly most particulate matter, and it's not even close. Comparing particulates to gas emissions is difficult, so there's no way to say what's "most".

Either way, my greater point still stands: switching to EVs isn't a cure-all to breathing around cars.

Sure, I suppose this is where I find umbrage with the claim. Instead of “most” maybe try “a comparable quantity of”? (I’d cut to the chase by clarifying tyres and brakes are the principle source of particulate matter, a pollutant with proven harms.)

They spread differently. CO2 affects the whole planet, more or less. Particulates settle in the nearby area. They're different things.

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