Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Electric cars produce less brake dust pollution than combustion-engine cars

modernengineeringmarvels.com

Post reply on HN
Print view View original

341–350 of 783 posts

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#341

Post by altairprime »

_fizz_buzz_ wrote: post #275
altairprime wrote: post #39

Earlier quoted context omitted.

If all of us renters were forced to convert to electric there’d never be an open charger in any city again for the next five years, because no landlord will voluntarily afford that cost, and no municipal region can pass a ballot measure to afford that cost. California’s impending ban of combustion car sales hinges wholly on a magical DC-charging network that doesn’t exist in U.S. cities yet (i.e. at parking meters),…

It's really not as big of deal anymore. My co-worker got an electric car and has his own house with a garage and never ended up installing a wall box. He simply charges at work or while buying groceries.

How many chargers per hundred spots do his work or grocery store have?

Typical car density for my nearest three grocery stores is 25-100 vehicles fluctuating during three or four peak hours. The highest number of chargers at any of those stores is 8, followed by 2 and 0; of those, 8 have been out of service for the past 60 days because someone is playing negotiation hardball with the charging services provider.

When the chargers were working, they were nearly at capacity for the entire day, at current (low) levels of electric car fraction of the population; there's no way they're prepared to cope with a full conversion, at which point the same power density and distribution problem that impacts multifamily parking garages instead (or as well!) affects grocery stores.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#342

Post by graemep »

webprofusion wrote: post #75
brtkwr wrote: post #4

An an EV owner, I can testify that the tyre wear more than makes up for the reduction in brake dust. I’ve had to change tyres every 10K miles.

Mine did more than 25,000, just get better tyres. The basic premise is that EVs are heavier and have more torque than average cars, but it's a 20% difference in real life, so your tyres may last 20% less.

Is it a linear relationship?

I know road damage is far higher (fourth power of weight) so maybe wear on tires is also worse than linear?

heavier vehicles are also worse in many other ways (e.g. less safe for pedestrians, require more space for parking,...) and we really should be encouraging smaller vehicles.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#343

Post by speedgoose »

Swizec wrote: post #106
ajross wrote: post #88

Earlier quoted context omitted.

To some extent, but not really. Effectiveness of regenerative braking depends on having an extremely large battery that can sink enough current to stop the car. An EV can do that, hybrids at best help the brakes out some. You just can't charge the battery fast enough doing anything but a very slow rolling stop. My model Y can effect a very reasonable stop in traffic without touching the brake pedal except to hold the…

> My model Y can effect a very reasonable stop in traffic without touching the brake pedal except to hold the car at the end. My manual car could do this 20 years ago. My fully ICE motorcycle can do it today. I know engine braking is cool but it’s not some amazing new thing only EVs can do. Altho granted it only produces heat and noise in petrol vehicles. But it also makes your heart sing so that’s nice

Can’t really compare the engine braking of a Model Y and a ICE vehicle to be honest.

I also like the noise, but it is noise pollution that is very annoying to everyone else.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#344

Post by altairprime »

xyst wrote: post #168
altairprime wrote: post #39

Earlier quoted context omitted.

If all of us renters were forced to convert to electric there’d never be an open charger in any city again for the next five years, because no landlord will voluntarily afford that cost, and no municipal region can pass a ballot measure to afford that cost. California’s impending ban of combustion car sales hinges wholly on a magical DC-charging network that doesn’t exist in U.S. cities yet (i.e. at parking meters),…

Car based transportation is just not scalable. Other countries have figured this out. Norway in particular. Working transportation models exist and this country has the funds to make it happen. However because of American Exceptionalism, we have very limited options.

This. This, this, this. I cannot stress enough how critical this point is. Either we invest a trillion dollars in electrifying parking spots or we invest that in building out transit and bicycling systems. None of them will ever be profitable over the long-run, so we continue with gas vehicles. I would so much prefer not to have to drive to the grocery store when I don't have 2 hours round-trip to spare on four intersecting transit schedules, or to risk life and limb every time I want to try and bicycle those 2.5 deadly miles across four highway on/offramps where vehicles ignore every "no turn on red" sign in the region and police that don't enforce.

Banning gasoline vehicles is the goal. In the U.S., all known solutions require capital investments that corporations can't extract a 'growth in profit growth over time' from, while disadvantaging the vehicle owners caste. Solve that, and you'll solve a lot more than just gasoline vehicles.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#345

Post by DaSHacka »

jajko wrote: post #284
3eb7988a1663 wrote: post #19

Earlier quoted context omitted.

I am just excited because the more EVs mean fewer idiots in hot rods running without mufflers.

Well there are new classes of idiots I see pretty frequently - a typical tesla driver going 90 in 120 region of highway without any reason, presumably saving last bits of battery (that has at least some rationale, if they do it due to ie fear then they should not be driving or having license). Over say 50km part of highway, maybe 2000 cars need to overtake such almost stationary object (to regular traffic which gener…

> going 90 in 120 region of highway without any reason, presumably saving last bits of battery (that has at least some rationale, if they do it due to ie fear then they should not be driving or having license).

Was very concerned until I realized you were talking about kilometers and not miles.

Otherwise, I'd hope the average driver would firce themselves to drive slower than 120mph out of some sense of fear, or at least a sense of self-preservation.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#346

Post by hvb2 »

usrusr wrote: post #285
pkolaczk wrote: post #271

Earlier quoted context omitted.

Another part of the point is that you can pack a much smaller and more efficient ICE and then substitute the missing power and torque from electric motors when needed. Most cars are not used at max power all the time. You need max power only at short times when accelerating. With pure ICE there is the tradeoff - a bigger engine will get you more max power / max torque but is going to be less fuel efficient because of…

On paper, yes, but did that ever happen? Sorry for being sarcastic, but where I live the frugal hybrid is exceptionally rare and the "same big engine, but driving a much heavier car" hybrid is omnipresent. The kind of people who might buy the frugal one buy second or third hand while almost all buyers of factory new pick the "same big engine" option, and those are the ones who decide what's available on the second ha…

Yes, every single prius for example? The biggest engine that was produced with seems to be a ~100 bhp engine which isn't much for a 1.5 metric tonne car

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#347

Post by yetihehe »

agurk wrote: post #328
MindSpunk wrote: post #312

Earlier quoted context omitted.

You're right. Petrol engines are air pumps so I should've realised the explanation wasn't correct. Though the ECU would be doing the AFR management on modern EFI engines as the injectors aren't vacuum operated like Carburetors were. You should be able to cut fuel injection when coasting in a modern engine, can't run lean if there's no fuel at all. Not sure if carbs could do the same.

On all the fuel injected engines I have owned there is a physical cable that controls the position of the throttle plate. There is an airflow mass sensor the other side of the plate to measure the amount of air and therefore how much fuel needs to be injected. So interestingly in these sort of engines you're really just controlling airflow to the engine rather than fuel/air mix like on one with a carburettor. More mo…

> Or do something like have the braking come on gently at first then harder.

You can do this by letting go of gas pedal slowly. I have "current amount of fuel used" info in my car (liters/100km), it shows pretty clearly, that when going fast and slowly letting go of gas, amount of fuels slowly goes to 0. If I let go of gas fast, the engine is intelligent enough to not close throttle as fast as possible, still probably takes 1 second.

> More modern engines have electronically controlled throttle plates, and this is definitely somewhere you could do something clever like you suggest - cutting fuel flow but also maximising airflow when there is zero throttle input.

They cut fuel flow and close throttle plate almost completely but still allow some small amount of air, in order to actually do engine braking. If you need to coast, you can apply clutch in manual. Don't know that much about automatic, but from what I've driven, they use "lift gas" as a "engine braking" signal, so probably they can't really coast that good.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#348

Post by pjc50 »

alexey-salmin wrote: post #243
rayiner wrote: post #16

We should obviously ban combustion engine cars, at least starting with cities. I can’t think of a single clearer win for air quality.

I can think of many. The list should start with coal power plants (hello, green Germany), then two-stroke engines (both mopeds and leaf blowers / lawn mowers), then diesel engines, especially diesel buses and trucks. None of that is in place. Modern gasoline and hybrid cars are fine, banning them at this point in time would mean a drop in quality of life for negligible gain.

Realistically this is what's happening in the UK with "low emission zones", the worst of the emitters are banned. Although public buses of course get an exemption until they can manage a changeover.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#349

Post by pmg101 »

mort96 wrote: post #278
pkolaczk wrote: post #271

Earlier quoted context omitted.

Another part of the point is that you can pack a much smaller and more efficient ICE and then substitute the missing power and torque from electric motors when needed. Most cars are not used at max power all the time. You need max power only at short times when accelerating. With pure ICE there is the tradeoff - a bigger engine will get you more max power / max torque but is going to be less fuel efficient because of…

And, you can make much lighter and lower range electric cars without all those heavy batteries, and boost the range with diesel when needed. Very attractive in principle. Most cars are not using their full range all the time, for a lot of people a 50 mile range car would be more than enough 98% of the time, but that remaining 2% means that people end up buying 200 mile range cars instead. But then, do you end up remo…

I thought about PHEV but in the end went full EV simply because it seemed to me with two whole power trains that's 2x the components to go wrong/need maintenance.

Re: Electric cars produce less brake dust pollution than combustion-engine cars

#350

Post by MindSpunk »

agurk wrote: post #328
MindSpunk wrote: post #312

Earlier quoted context omitted.

You're right. Petrol engines are air pumps so I should've realised the explanation wasn't correct. Though the ECU would be doing the AFR management on modern EFI engines as the injectors aren't vacuum operated like Carburetors were. You should be able to cut fuel injection when coasting in a modern engine, can't run lean if there's no fuel at all. Not sure if carbs could do the same.

On all the fuel injected engines I have owned there is a physical cable that controls the position of the throttle plate. There is an airflow mass sensor the other side of the plate to measure the amount of air and therefore how much fuel needs to be injected. So interestingly in these sort of engines you're really just controlling airflow to the engine rather than fuel/air mix like on one with a carburettor. More mo…

I've got both at the moment on my two Hondas. Both manual, one with a throttle cable and one with throttle-by-wire. There's quite a bit of difference in how they handle off throttle. The cable will just slam the throttle shut if you just jump off the pedal (obviously) and it jerks pretty hard. The throttle-by-wire car hangs the throttle a little when letting off and doesn't just immediately start decelerating. Then it's much smoother once it does start slowing down. The ECU definitely doing something to smooth it out.

Funny because the cars build dates are only 2 years apart, 2005 and 2007, and they're both K20 engines but the engines handle so different.

Post reply on HN