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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

#681

Post by kube-system »

supportengineer wrote: post #676
cperciva wrote: post #176

Earlier quoted context omitted.

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.

In order to do this with a gas engine, it can be done but you need to completely mechanically decouple the gas engine from the drivetrain. The gas engine needs to do one thing and one thing only which is charge the battery. The gas engine has maximum efficiency at about 80% throttle.

The efficiency of the entire system is more important than the efficiency of the engine itself. Charging the battery and then discharging it also incurs losses. Many series hybrids will prioritize generating electricity when some of it is also required to directly drive the motor. They usually don't sit around at low-load situations just generating electricity, unless SOC is low.

> The gas engine has maximum efficiency at about 80% throttle.

ICE efficiency varies in multiple dimensions based on load and RPM, and in a series hybrid, you have some ability to dynamically influence these... throttle would be one of those inputs.

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

#682

Post by supportengineer »

dotancohen wrote: post #203
MindSpunk wrote: post #154

Earlier quoted context omitted.

You don't engine brake with the clutch, you engine brake by downshifting and using the higher engine RPM in lower gears to brake the car via wasted compression.

And that downshifting involves a clutch operation, moving the engine into a higher RPM. That most certainly wears down the clutch, talking as someone who's replaced quite a few of them.

Clutch wear occurs when the clutch is slipping so you always want to minimize the slipping time.

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

#683

Post by tim333 »

atoav wrote: post #647

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…

Tricky to do accurately though. Like a car driven occasionally in the countryside may cause little damage from brake dust, a cab in a city center a lot.

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

#684

Post by chasd00 »

ohdeargodno wrote: post #476
graemep wrote: post #376

Earlier quoted context omitted.

The info is useful, but those do not seem to be all that small. There were smaller engines available for the ICE version of the Clio, for example.

There was, and it was shit. The Cléon-Fonte, despite all my love for its BBBBRRRRRRRRRRVVVVVVVVVVV was becoming wildly insufficient for the already ever heavier cars simply due to electronics and safety measures, and it was already a 1.2L. The smallest ever put on a Clio was a .999L, and anyone driving a Twingo knows how it behaves the moment there's... a slight incline, or two people in the care. 1.5L is an incredib…

I feel like I remember a pickup being available that was a 6L v8. So one cylinder in that engine had almost the same volume as all the cylinders in a 1.5L engine combined. That's pretty crazy to me.

edit: oh it was mine heh, my first car was a 1979 ford with a 460 ( 7.5L v8 ). It was a hand me down from my grandfather, he said if i could get it running i could have it.

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

#685

Post by whycome »

Finnucane wrote: post #634
whycome wrote: post #588

Earlier quoted context omitted.

With a manual car, it was common to downshift and use the engine to decelerate. I’m wondering if electric vehicles might actually cause a return to a third pedal to re-add some of the fine tuned controls that a manual transmission allowed. Maybe the “downshift” could engage the regen brake specifically.

'common'? When I was a young'n, I was taught that that was basically an emergency procedure to use if the brakes failed, to force the car to slow down. I can't imagine wanting to do that routinely.

My car (an old Jetta) lasted ~20 years and was still good to go when I got rid of it. Only the body itself had any issues. I suppose the use would vary based on terrain? It was useful to get to a gear with more torque for taking off again. And I guess you’re not doing it from really high revs — so it was just using the engine to slow things

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

#686

Post by stavros »

Swizec wrote: post #672
stavros wrote: post #290

Earlier quoted context omitted.

I have an ICE car and motorcycle, and an EV. The EV slows down much more quickly when slowing down, to the point where it's a good replacement for the brake, as opposed to the ICE vehicles, where you need to use the brake a lot more. It's not comparable.

> The EV slows down much more quickly when slowing down, to the point where it's a good replacement for the brake Are you comparing to an automatic ICE or a manual? In my experience of driving EVs their engine braking is sub-par to what I'm used to at least from my motorcycle. Bikes have silly high compression compared to their weight. You def have to be careful about chopping the throttle.

An automatic, with a manual you can shift down to whatever you want, so there's no standard there, really.

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

#687

Post by MrDunham »

jgilias wrote: post #674
whycome wrote: post #588

Earlier quoted context omitted.

With a manual car, it was common to downshift and use the engine to decelerate. I’m wondering if electric vehicles might actually cause a return to a third pedal to re-add some of the fine tuned controls that a manual transmission allowed. Maybe the “downshift” could engage the regen brake specifically.

Was it that common? Where I’m from that’s “winter driving mode” because it’s safer on slippery surfaces, but rarely anyone would do that in the summer time. My EV is set on max regen mode though, and I sometimes drive without pressing the brakes, as there’s a paddle I can use to use regen for all my braking needs bar an emergency. It even has a name - single pedal driving.

Can't speak to if it's common, but it was how I was taught and drove in California... so there was rarely any winter conditions to speak of.

I preferred downshifting VS braking, personally

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

#688

Post by morkalork »

mnw21cam wrote: post #644
Finnucane wrote: post #634

Earlier quoted context omitted.

'common'? When I was a young'n, I was taught that that was basically an emergency procedure to use if the brakes failed, to force the car to slow down. I can't imagine wanting to do that routinely.

If you drive down any significant hill, you either use engine braking, or you overheat your brakes. It's a fairly basic part of driving tuition and the driving test for a good reason.

When I visited a nearby observatory it was fun driving on the mountain and seeing the signs telling you to use engine braking on the way down and trying it for the first time.

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

#689

Post by sjducb »

infecto wrote: post #436
sjducb wrote: post #317

Earlier quoted context omitted.

Agreed parent needs to get advice from 2/3 different tyre shops. Changing tyres every 10k means something is wrong.

That or just slow down. I swear 90% of the people that complain of tire wear drive oblivious and are flooring it after every stop. Even a Kia Beri which what the parent has, has more kick than a ICE.

Maybe, I think the tyre shop is encouraging premature tyre changes. My local tyre shop recommends changing the tyres at 3.9mm. The tyre’s data sheet says it’s ok down to 1.6mm. You’re wasting 2.3mm of tyre, which is 30% of the life of the tyre.

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

#690

Post by RankingMember »

prova_modena wrote: post #633
Eric_WVGG wrote: post #632

Earlier quoted context omitted.

I used to do that with a vintage 70's sportscar… later learned that it was pretty bad for the long-term life of the transmission so had to train myself out of it.

It's gentle on the transmission and clutch if you rev match on the downshifts.

Also fun! Half the fun of a manual for me is double-clutching (totally not necessary unless you have no synchros but it's a fun challenge) and nailing the rev-match on a downshift.
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