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Dust from car brakes more harmful than exhaust, study finds

e360.yale.edu

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Re: Dust from car brakes more harmful than exhaust, study finds

#401

Post by malfist »

patmorgan23 wrote: post #370
malfist wrote: post #355

Earlier quoted context omitted.

Road wear? Not really. Tire wear? In the strictest sense, yes. But keep in mind, a lot of those studies measured "ev" tire wear by throwing a bunch of weight into the trunk of a gas car. Not exactly the same thing. Holistically, particle emissions from EVs are lower than gas powered cars due to reduced breaking (even above hybrids) and reduced exhaust. At the end of the day, the vast vast vast majority of road wear a…

Isn't road wear scale with the 4th power of vehicle weight? EV vehicle weight definitely moves some needles in the wrong direction. A Toyota Corolla weighs about 3,000, the Tesla model 3 weighs 3,500-4,000 depending on which model you buy. So a 16-33% increase in vehicle weight. A Corolla will do 8.1 x 10^13 'damage points' A light model 3, 1.5 x10^14 'damage points' And a heavy model 3, 2.6x10^14 So moving to EV veh…

Garbage trucks aren't exactly a good comparison here.

Your typical empty semi truck weighs 35k pounds, and a lot more when loaded. There's also more miles driven by semi trucks than passenger vehicles

Re: Dust from car brakes more harmful than exhaust, study finds

#402

Post by guenthert »

mcv wrote: post #378
WillPostForFood wrote: post #342

Earlier quoted context omitted.

The comment you replied to mentioned EV tire wear, not brake dust. The heavy weight of EVs due to the batteries is always going to cause more tire pollution. E.g., Ford F-150 Ford Lightning has a curb weight of up to 6,500 lbs, which compares to the regular F-150's curb weight that ranges from anywhere between 4,021 lbs and 5,014 lbs. The Rivian R1T is 7,148 lbs.

That's more an argument against SUVs and heavy pickup trucks than against EVs, though.

Well yes, but even the Renault Zoe at 3,236lbs is much heavier than the Renault Clio (2,161–2,361lbs) it is based on.

Heavier weight alone however doesn't necessarily cause more tire wear though. The Toyota Prius came with hard-compound tires (good for low fuel consumption and high mileage, not for racing).

Re: Dust from car brakes more harmful than exhaust, study finds

#403

Post by guenthert »

tbossanova wrote: post #385
superjan wrote: post #300

Earlier quoted context omitted.

They do. But if you brake too agressively, they switch to friction brakes. It pays off to avoid this: more mileage, marginally lower charging expense, lower cost on brake maintenance and fewer complaints from passengers.

Apparently you need to use the friction brakes now and then so they don’t degrade early, which could be a safety issue. I think as long as you’re using the car frequently it’s incredibly unlikely to be a problem though.

Not sure about all EVs and hybrids, but for Prius the friction brakes were used below a given speed as then regeneration becomes inefficient (as does stopping power). If you pay close attention, you might notice the transition.

Re: Dust from car brakes more harmful than exhaust, study finds

#404

Post by guenthert »

jgalt212 wrote: post #329
aaron_m04 wrote: post #254

Earlier quoted context omitted.

If you have an EV and you care about health and the environment, use regenerative braking as much as humanly possible. Hint: driving fast or tailgating both increase the odds you'll have to use the friction brakes.

The problem is that not all cars correctly illuminate the brake lights when regenerative braking is in effect.

I doubt that this is really the case (brake lights will be connected to brake pedal, regardless of mode).

For motorcycles (not using regenerative braking, but engine braking which is quite effective there) this however is a problem. Every once in a while I woke a sleepy tailgater with that. Fortunately all sleepy tailgaters did wake up in time.

Re: Dust from car brakes more harmful than exhaust, study finds

#405

Post by bobsmooth »

93po wrote: post #232
bobsmooth wrote: post #199

Earlier quoted context omitted.

I live on the second floor near a road and my balcony furniture is always covered in black gunk.

do you have an air filter with an ionizer by chance? those will also do that

An air filter on my balcony?

Re: Dust from car brakes more harmful than exhaust, study finds

#406

Post by adgjlsfhk1 »

Tade0 wrote: post #357
orev wrote: post #88

The Yale article and the paper both highlight the fact that EVs use regenerative braking and produce less dust. I was worried that this was a rehash of the astroturf campaign from a few years ago focusing on EV weight and how that was so bad for the environment because of tire and road wear. Unfortunately you need to read through the whole thing (instead of the headline and a few paragraphs) to see that information.

I think someone eventually pointed out that a typical bus weighs around 10x that of a car while having maybe twice the tyre surface area in contact with the ground. According to the 4th power law that translates to 625x the road (and thus also tyre) wear, meaning even a fully loaded bus should produce significantly more particulates than the equivalent in cars with just one occupant each.

yeah this is very wrong. air pressure, acceleration and tire compound make a huge difference in tire wear

Re: Dust from car brakes more harmful than exhaust, study finds

#407

Post by stuaxo »

BossingAround wrote: post #384
iterateoften wrote: post #12

Having lived next to a semi-main street through a smallish California coastal city without much rain it is pretty eye opening how much black dirt and junk just coat everything next to the road. Walk down the street and touch a bush or any plant leaf and get a nice black hand in the process. The plants are covered, parked cars get covered and the inside of my apartment was covered. It wasn’t until I moved out that I s…

Wouldn't this be very well mitigated by the use of an air purifier?

Or MVHR in the home for a more permanent fix.

Re: Dust from car brakes more harmful than exhaust, study finds

#408

Post by MichaelZuo »

BizarreByte wrote: post #253
iterateoften wrote: post #12

Having lived next to a semi-main street through a smallish California coastal city without much rain it is pretty eye opening how much black dirt and junk just coat everything next to the road. Walk down the street and touch a bush or any plant leaf and get a nice black hand in the process. The plants are covered, parked cars get covered and the inside of my apartment was covered. It wasn’t until I moved out that I s…

> Having lived next to a semi-main street through a smallish California coastal city without much rain it is pretty eye opening how much black dirt and junk just coat everything next to the road. One day I made the mistake of leaning against the wall in a TTC subway station while in a white shirt. I didn't realize how much oil, brake dust, and other mechanical grime there was until that moment. I had to go home and c…

I think some research group did measurements of the AQI in the TTC stations and found the average air quality in the winter was actually comparable with the smog in LA or Beijing.

Re: Dust from car brakes more harmful than exhaust, study finds

#409

Post by Schiendelman »

benlivengood wrote: post #341
Schiendelman wrote: post #307

Earlier quoted context omitted.

Yes, and yes. Though with a lower mass vehicle you may have reduced grip.

Grip is proportional to downforce times the coefficients of friction. Since downforce comes mostly from vehicle weight the maximum available acceleration/deceleration (grip) is nearly identical across lighter and heavier vehicles for a given tire compound and tread pattern. The complexity comes from things like sidewall stiffness (controls available grip near the lateral limit of traction, must be designed for vehicl…

"Since downforce comes mostly from vehicle weight the maximum available acceleration/deceleration (grip) is nearly identical across lighter and heavier vehicles for a given tire compound and tread pattern."

What? Was this written by AI?

Re: Dust from car brakes more harmful than exhaust, study finds

#410

Post by tenuousemphasis »

caycep wrote: post #212
orev wrote: post #88

The Yale article and the paper both highlight the fact that EVs use regenerative braking and produce less dust. I was worried that this was a rehash of the astroturf campaign from a few years ago focusing on EV weight and how that was so bad for the environment because of tire and road wear. Unfortunately you need to read through the whole thing (instead of the headline and a few paragraphs) to see that information.

Granted, I would still rather them designed for lighter weight. But that’s a separate issue w suv culture which is bad for society and environment in general. Totally would buy a 3000 pound EV around the size of a euro hatch.

There's the Fiat 500e
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