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

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

#421

Post by boesboes »

Dylan16807 wrote: post #247
alexey-salmin wrote: post #243

Earlier quoted context omitted.

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.

Diesel transport trucks and busses are getting a lot of work done per gallon. How much worse are their emissions? Hybrid cars might be good enough, but banning pure combustion cars from cities sounds perfectly reasonable to me. No real quality of life impact.

And how are we going to charge all those EV's? the grid is already overloaded in many places. Here we are requested to not charge our cars during certain times to reduce load.

And how will all the people that are buying 500€ second hand cars afford electric?

Don't get me wrong, I think there is merit in a ICE free future, especially in urban areas, but the practicalities.. And I am not convinced the long term impacts of EV are fully appreciated necessarily.

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

#422

Post by potato3732842 »

pengaru wrote: post #104
idiotsecant wrote: post #86

Earlier quoted context omitted.

Low friction tires wear slower, not faster, on account of being ... Low friction. Friction is what wears tires.

> Low friction tires wear slower, not faster, on account of being ... Low friction. Friction is what wears tires. They're not low friction tires, they're low rolling resistance tires. Friction relates to the grip, rolling resistance relates to the heat generated by the deformation of the tire. A less compliant, often narrower tire may wear faster than a more compliant wider one. It depends. "Tyres account for about a…

>They're not low friction tires, they're low rolling resistance tires.

Those two attributes are pretty decently tied together, can't get one attribute maxed out without a solid showing of the other.

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

#423

Post by vladvasiliu »

MindSpunk wrote: post #186
cloverich wrote: post #153

Earlier quoted context omitted.

Surprisingly you can get nearly same effect in automatics. I put around 60k miles on my first automatic (after120k+ on my first two cars, manual transmissions) and when i got my brakes checked at 63k they noted my brakes were still "brand new". I do gamify reading traffic to try and brake as little as possible (to help pass time etc), but was still surprised how far this takes you given i do plenty of stop and go tra…

It's not "nearly". It's exactly the same effect. Compression braking. Even if you're not on the throttle the engine is still rotating as it's connected to the wheels. If the engine is rotating it is compressing air. If it's compressing air but not igniting fuel (throttle closed) then it will suck energy out of the wheels to compress the air. You can do it in an automatic, you just have to force it to select a lower g…

It depends on the implementation. I ride an automatic motorbike which will downshift if I grab the brakes a bit harder, even if I'm only slowing to a speed to which it wouldn't otherwise shift.

For example, if I brake somewhat hard from 130 km/h to 90, it will downshift from 6th to 5th. When riding normally, it would stay in 6th down to around 50.

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

#424

Post by mmaurizi »

30gdan wrote: post #405
stephen_g wrote: post #5

Good to have more data points and evidence, but this seems extremely well established by now? Zero tailpipe emissions, drastically removed brake dust, slightly higher tire wear (due to weight), but much better overall than ICE.

Much better at what ? Do you have decent data for what it takes (CO2, child labour , cost of supply chain, ...) to make your Lithium based battery VS melting an ICE ? Same question for recycling ? Comparing only the lifecycles of products doesn't make any sense if you don't put in perspective creation & destruction and this is where the massive lie is, no EV constructor has ever been transparent about this because it…

Ships are actually much more fuel efficient than trucks, by weight/volume.

Saying it must be inefficient because it includes ship transit instead of trucking "locally" is innumerate.

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

#425

Post by ZeroGravitas »

nine_k wrote: post #41

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. [1]: https://www.consumeraffairs.com/automotive/how-many-electric...

Yes, but only to some degree.

Quote from the actual report:

> As the level of electrification of a vehicle rises, the dependence on regenerative braking also increases, thus lowering PM emissions from brake wear. Based on recent evidence [30], regenerative braking can reduce, in the worst- case scenario (i.e. highest usage of mechanical brakes or equivalently lowest usage of regenerative braking), brake wear emissions by 10-48% for hybrid electric vehicles (HEVs), 66% for plug-in hybrid electric vehicles (PHEVs), and 83% for battery electric vehicles (BEVs

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

#426

Post by vladvasiliu »

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…

> it could be fun to be able to customise the amount

Some recentish motorbikes have an option to customise the amount of engine brake, I suppose cars could have something similar, too.

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

#427

Post by CraigJPerry »

Dylan16807 wrote: post #229
CraigJPerry wrote: post #181

Earlier quoted context omitted.

100% of possible system capacity to accept regenerative charge on a smaller battery system will be a smaller absolute number than 100% of possible on a larger battery. If you assume everything else is constant, motor, inverter, battery C-rating etc.

I'm not sure what you're arguing here. Bigger battery is more capacity sure. But their point was that even without a big battery they have enough capacity to get close to maximum effectiveness, contrary to ajross saying that a hybrid's capacity is "not really" effective and "at best" helps "some".

just mistaken about maximum effectiveness

braking system = circa 1G of deceleration possible (depending on tyres, coeff of friction, temperature, ... etc etc)

So max effectiveness is unreachable for any regen system on a consumer car hybrid or ev, by a factor of around 6x i believe?

With recognition of the mistaken framing (near max effectiveness) we're back to the larger ev pack has a greater ability to sink current, a larger ability to slow the vehicle than does a smaller battery (obvious considerations about inverter capability, wire gauge etc etc aside)

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

#428

Post by SigmundA »

cperciva wrote: post #176
nine_k wrote: post #41

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. [1]: https://www.consumeraffairs.com/automotive/how-many-electric...

which is the whole point of hybrids Part of the point, not the whole point. Regenerative breaking is absolutely a win; but there can also be a significant benefit from allowing the ICE to remain in the RPM "sweet spot" rather than moving around a larger range.

Most hybrids on the road are parallel and have a mechanical connection to wheels and vary rpm as needed, although the CVT implementations may hold rpm due to gear ratios like any CVT hybrid or not.

A direct mechanical connection is more efficient at highway cruise speeds than a mechanical->electric->mechanical conversion.

The main win a gasoline hybrid has is in running the Atkinson cycle gaining efficiency while losing torque which the electric motor makes up. This brings the gasoline engine up into diesel efficiency territory.

This is also why you don't really diesel hybrids, the engine is already very efficient but it is more expensive and heavier and hybrid adds more expense and weight.

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

#429

Post by infecto »

nine_k wrote: post #41

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. [1]: https://www.consumeraffairs.com/automotive/how-many-electric...

I have not seen many if any Hybrids that use regen to the same degree as an EV.

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

#430

Post by CraigJPerry »

tbrownaw wrote: post #191
CraigJPerry wrote: post #181

Earlier quoted context omitted.

100% of possible system capacity to accept regenerative charge on a smaller battery system will be a smaller absolute number than 100% of possible on a larger battery. If you assume everything else is constant, motor, inverter, battery C-rating etc.

The manual says it's energy recovered (ie, not something relative to system capacity), and this seems consistent with the other indicator that shows instantaneous braking power with a distinction between what the regenerative system is doing vs what (if anything) the traditional brakes are doing.

which car? i think the number you're referring to is relative to electrical system capacity.

It's NOT relevant to overall (tyre, brake system & engine braking & regen braking) braking system performance since that's a dynamic value variable over many factors constantly.

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