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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

#651

Post by stavros »

eldaisfish wrote: post #438
stavros wrote: post #370

Earlier quoted context omitted.

Hmm, I don't really understand what you mean. If I want to reduce speed far ahead, I just ease up on the throttle pedal a little, and the car slows down a little. If I ease up a lot, it slows down a lot. I'm not sure what you mean...

regenerative braking can be uncomfortable for passengers as the car is constantly alternating between accelerating (or constant speed) and braking. It isn't even light braking, it is significant braking. I generally turn off the auto regen braking because i find it uncomfortable. Importantly, regenerative braking is a danger on icy roads. I disable it entirely in the winter in eastern Canada because it often causes t…

I agree about the icy roads, but for the braking, that's easily remedied by just not completely releasing the accelerator. I just modulate how much I want to brake with the accelerator pedal.

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

#652

Post by klaff »

taeric wrote: post #637
klaff wrote: post #627

Earlier quoted context omitted.

I have a Subaru (ten years old w/ >200k miles on it's chain-type CVT), and I thought the justification for it was that it was more efficient than previous systems. From a mechanical engineering standpoint, the Subaru CVT uses a fairly conventional lock-up torque converter at the input, but that gets locked as you pass something like 15-20 mph (once the lowest gear ratio is satisfactory w/o the torque converter functi…

My understanding is that the overall system is more efficient. It is only the transmission that is less so. The videos online that look at various CVT systems is truly an amazing resource that I regret not having when I was younger. :D

If overall efficiency is what you see reflected in the EPA mileage numbers (or similar European tests), in what scenario would a lower efficiency transmission (lower Pout/Pin over some range of operating points?) lead to or even allow better overall efficiency?

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

#653

Post by Symbiote »

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.

Meant German cities have electric or natural gas buses. Electric local delivery vans are becoming more common.

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

#654

Post by jjtheblunt »

dotancohen wrote: post #649

> The health effect is especially critical for urban disadvantaged groups, where exposure to partical matter has been shown to be related to increased asthma rates, cardiovascular disease, and other respiratory conditions. Why would the health effect be more critical for disadvantaged groups than for other urban groups?

perhaps the disadvantage is that, over time, living nearest to traffic _is_ the disadvantage, as it means living most immediately near pollution concentration.

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

#655

Post by tim333 »

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…

Fiat 500 hybrid 999cc engine, 69bhp (51kW).

I hired one on holiday and it worked fine. Maybe I'm getting old but I see less point in getting something that does 0-60 in 4 sec when most traffic goes from 0-40 in about two minutes and doesn't get much faster. It still has a top speed over 100mph.

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

#656

Post by OkayPhysicist »

whycome wrote: post #588
janosch_123 wrote: post #540

For DIY EV conversions (I built some cars) you usually hook up the "regenerate braking" to the brakelight switch. So as soon as you tap the brake pedal just a little, you start regenerating and see the amps flow back into the battery (I have a little display on my dashboard). Only when you press the pedal further, do you start engaging the friction brakes. I have no statistics on brake pad differences because we didn…

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.

My Bolt has a hand paddle behind the steering wheel that engages regenerative brakes (and only the regenerative brakes). I make use of it extensively. When in "single pedal" (where the accelerator acts as a speed selector, i.e., the car brakes when you step off the 'gas'), it's a lot more aggressive than just lifting my foot off the pedal, and when in "simulate an automatic transmission" 2 pedal mode, I find the paddle is easier than figuring out exactly where the threshold is on my brake pedal between regen and friction brakes.

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

#657

Post by polairscience »

dotancohen wrote: post #649

> The health effect is especially critical for urban disadvantaged groups, where exposure to partical matter has been shown to be related to increased asthma rates, cardiovascular disease, and other respiratory conditions. Why would the health effect be more critical for disadvantaged groups than for other urban groups?

Sincere reply assuming sincere question, the implication is that they are statistically much more likely to live near interstates and highways. Since historically land owned by poor 'disadvantaged groups' has been easier for state and federal governments to get their hands on.

The sentence, while poorly written, isn't saying that "health impacts don't matter for 'non-disadvantaged people'". A reading that is disingenuous.

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

#658

Post by kube-system »

toss1 wrote: post #605
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.

Cool idea. Perhaps a better idea would be to borrow from the brake balance adjustment in race cars, wherein an adjuster dial/knob allows the driver to alter the balance between the front vs rear brakes when the brakes are applied (very useful in wet vs dry conditions, high-speed vs low-speed sections, etc.). So, instead of adjusting the F-R brake balance, the dial could adjust the regen-vs-mechanical braking, up to t…

Pretty much all hybrids already do this, but automatically. When you press the brake pedal, they will command regen first, and only the hydraulic brakes under conditions when regen is not enough.

Series hybrids also have the ability to dump excess power just like you are suggesting as well. Instead of resistor banks (like trains) they often dump energy by using the generator to spin the engine… literally engine braking.

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

#659

Post by thijson »

thmsths wrote: post #571
eftpotrm wrote: post #414

Earlier quoted context omitted.

BMW tried that with the i3, it wasn't particularly popular. An engine, fuel system and a generator are all relatively complex additions compared to just putting the same cost and vehicle space into more batteries, and the public charging networks are definitely up to the task by now (having been EV-only for almost 5 years now).

I've ridden in one and this was basically a case of "you get the worst of both worlds". The engine was small and running at a constant RPM, leading to an annoying noise in the cabin. The range extension was not particularly huge. Worse, when we did eventually run out of battery on one trip, the range extender was unable to recharge the battery after refueling the car, forcing us to scramble to find an available charg…

I've been driving one for a while. On the trips I've driven, even on the highway, the engine was able to keep up with the energy draw. I think it's around 60HP. If I'm on a long trip, I'll start the engine once I reach 75% of my battery capacity. That gives a significant buffer for the engine. It's a serial hybrid.

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

#660

Post by [deleted] »

toss1 wrote: post #605
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.

Cool idea. Perhaps a better idea would be to borrow from the brake balance adjustment in race cars, wherein an adjuster dial/knob allows the driver to alter the balance between the front vs rear brakes when the brakes are applied (very useful in wet vs dry conditions, high-speed vs low-speed sections, etc.). So, instead of adjusting the F-R brake balance, the dial could adjust the regen-vs-mechanical braking, up to t…

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