6 ms·

and would it be true to say that regenerative braking on electric cars reduces significantly this dust?

thmsths 10mo ago
I recall a discussion on HN explaining that while true, this might be offset by the higher average weight of EVs, leading to more dust from the tires and the road. Again, no easy solution unfortunately, just trade offs.
- iambateman 10mo ago
  If that were true of tires, you would expect an EV’s tires to get substantially less range before wearing out…which I don’t believe is the case.
  - pif 10mo ago
    It is actually the case! That's why your choice of tires on online sites gets so smaller as soon as you tuck the "electric/hybrid vehicle" case!
    - t_tsonev 10mo ago
      Specialized EV tires are also optimized for drag and noise, wear is just a factor. Anecdotally speaking I'm at over 80k km on a set of EV tires with at least 20k more to go. The issue has more to do with driving style and engine power than any other factors.
      - l1tany11 10mo ago
        100%. Tire technology is a real thing. Tires have advanced a ton in the last 10 years. But driving style is the biggest thing. Some people can only get 10k miles out of a set of tires, while others with the same car and tires get over 40k. But they do care about tire wear a lot, they know the acceptable wear life for the class. A couple years ago I bought a set of Pirelli tires that were ~50% off because they were an older version; hoping I’d get some benefit. Unfortunately they had half the life and were a bit worse in every way than the newer tires I had before and after.
        bob1029 10mo ago
        Some tires are going to wear fast no matter what. I had some Pirelli PZero summer tires that I could never get more than 15k out of regardless of how I drove. The tire compound was very soft and sticky. If you have something like really high performance tires, I recommend just using them. The grip is always there and you are always paying for it. As long as you aren't losing traction constantly, the difference is negligible in my experience.
  - rconti 10mo ago
    IME they only wear out maybe 15-20% faster than you'd think. On the other hand, over the span of 40,000 miles, a tire loses a LOT more rubber by weight/volume than a brake pad loses pad material. No idea what the PM2.5 breakdown is though.
    - bryanlarsen 10mo ago
      The difference is that only about 1% of the worn rubber ends up in the air whereas most of the brake pad ends up in the air. Most of the worn rubber stays on the road. Where it will get washed away by the rain to end up as microplastics in the water.
- coryrc 10mo ago
  Additional weight (which is minor; of best-selling vehicles, F-150 curb weight is 4000-5600 lbs, Tesla Model Y is 4400-4600 lbs) does not meaningfully increase brake wear because the brakes don't get used.
- coryrc 10mo ago
  And to add info, an F-150 will change brake pads 3-7 times over 200k miles, while a Model Y will still be on the original set with nearly no sign of wear.
  - fsckboy 10mo ago
    but compare the wear of the tires, and weigh tires vs brakes by the amount of "total pollution delivered to the environment", i.e. 20% more wear of something that is 2x as polluting is 40% more pollution. I don't know the numbers or the answer, I'm just saying it's not as simple as your statement makes it out to be.
    - brailsafe 10mo ago
      > 20% more wear of something that is 2x as polluting is 40% more pollution If an equivalent car wore down its tires 20% slower, and those tire particles contributed 2x the intensity of pollution than other types of wear-based pollution, than the increase in produced pollution from that source seems like it would be ~16%, not 40%. If one car drives 100 km and produces 2 units of pollution per km, that would be 200 units. Another car wearing 20% more would produce 240 units, or roughly ~16% more.
      - yunwal 10mo ago
        > Another car wearing 20% more would produce 240 units, or roughly ~16% more. This is some Fermat’s Last Theorem shit
    - coryrc 10mo ago
      Why are you just making up numbers then saying "it's not as simple"? Try educating yourself a little first instead of just jumping to conclusions which reinforce your existing biases.
- rcpt 10mo ago
  That sounds like a stretch tbh
coryrc 10mo ago
Absolutely. Nearly eliminates. Even non-plugin hybrids have greatly reduced. There was a "study" going around claiming otherwise, which sampled air captured by passing vehicles with a trash bag on a busy road, claiming EVs did not reduce brake dust, but even my brief summary here makes it extremely obvious how flawed this "measurement" is.
- margalabargala 10mo ago
  For those of us unclear why collecting air from passing cars to measure particulates is obviously flawed, could you elaborate? EVs unfortunately do increase tire particulate, as well. Fairly significantly. It's not obvious to me that the decrease in brake dust isn't made up by the increase in tire dust. The removal of the tailpipe emissions is really where EVs shine from a pollution standpoint. If you turn on your car in your garage, you don't die anymore.
  - coryrc 10mo ago
    EV brake pads don't hardly wear down, so they obviously can't have nearly the same amount of brake dust, yet the "study" showed they did. I'm guessing there's brake dust on the ground being kicked up. > EVs unfortunately do increase tire particulate, Fairly significantly In the USA, mass of EV is not significantly different than the alternative choice. EVs do not have increased tire particulate. If in Europe extremely lightweight tiny cars are actually a likely substitution for nicer, heavier EVs, then it seems reasonable that tire wear will increase proportionally. There's a lot riding on that "if" though.
    - margalabargala 10mo ago
      It's not just the fact that EVs are heavier than the non-EV version of the same car, it's also that the regenerative braking means that the tires are dissapating energy that otherwise would have gone to the brake pads or to air resistance. Tires wear way faster on an EV, their lifespan in miles is generally much shorter.
      - 10mo ago
kjkjadksj 10mo ago
You can get this lack of brake pad use with an ice with a manual transmission as well if you engine brake.
- shayief 10mo ago
  the engine cannot brake to a complete stop, so break pads are always in use. At low RPMs, the engine is going to stall (manual) or switch to neutral (automatic).
  - kjkjadksj 10mo ago
    It can brake to nearly a complete stop though with the brakes basically holding the car in place at the end. I got pretty good at it.
  - bob1029 10mo ago
    Brake wear scales ~quadratically with vehicle speed. Applying them at 5mph vs 20mph is 16x less energy to burn off.
earlyreturns 10mo ago
I’m guessing not as much as standard transmissions, which largely eliminate the need for breaking while also reducing fuel usage. Yet there are almost no new cars with standard transmission. If only people cared a bit more.
- bryanlarsen 10mo ago
  You guessed wrong. An electric car can use its engines to bring a vehicle to a complete stop. It can also use the motor to hold the car in place, even on a fairly steep incline. You can't do either with a standard transmission ICE vehicle. There are people with electric cars that have their brakes rust out because they're never used. A standard piece of advice to EV owners is "make sure to use your brakes at least once a month".

I recall a discussion on HN explaining that while true, this might be offset by the higher average weight of EVs, leading to more dust from the tires and the road. Again, no easy solution unfortunately, just trade offs.

iambateman 10mo ago
If that were true of tires, you would expect an EV’s tires to get substantially less range before wearing out…which I don’t believe is the case.
- pif 10mo ago
  It is actually the case! That's why your choice of tires on online sites gets so smaller as soon as you tuck the "electric/hybrid vehicle" case!
  - t_tsonev 10mo ago
    Specialized EV tires are also optimized for drag and noise, wear is just a factor. Anecdotally speaking I'm at over 80k km on a set of EV tires with at least 20k more to go. The issue has more to do with driving style and engine power than any other factors.
    - l1tany11 10mo ago
      100%. Tire technology is a real thing. Tires have advanced a ton in the last 10 years. But driving style is the biggest thing. Some people can only get 10k miles out of a set of tires, while others with the same car and tires get over 40k. But they do care about tire wear a lot, they know the acceptable wear life for the class. A couple years ago I bought a set of Pirelli tires that were ~50% off because they were an older version; hoping I’d get some benefit. Unfortunately they had half the life and were a bit worse in every way than the newer tires I had before and after.
      - bob1029 10mo ago
        Some tires are going to wear fast no matter what. I had some Pirelli PZero summer tires that I could never get more than 15k out of regardless of how I drove. The tire compound was very soft and sticky. If you have something like really high performance tires, I recommend just using them. The grip is always there and you are always paying for it. As long as you aren't losing traction constantly, the difference is negligible in my experience.
- rconti 10mo ago
  IME they only wear out maybe 15-20% faster than you'd think. On the other hand, over the span of 40,000 miles, a tire loses a LOT more rubber by weight/volume than a brake pad loses pad material. No idea what the PM2.5 breakdown is though.
  - bryanlarsen 10mo ago
    The difference is that only about 1% of the worn rubber ends up in the air whereas most of the brake pad ends up in the air. Most of the worn rubber stays on the road. Where it will get washed away by the rain to end up as microplastics in the water.
coryrc 10mo ago
Additional weight (which is minor; of best-selling vehicles, F-150 curb weight is 4000-5600 lbs, Tesla Model Y is 4400-4600 lbs) does not meaningfully increase brake wear because the brakes don't get used.
coryrc 10mo ago
And to add info, an F-150 will change brake pads 3-7 times over 200k miles, while a Model Y will still be on the original set with nearly no sign of wear.
- fsckboy 10mo ago
  but compare the wear of the tires, and weigh tires vs brakes by the amount of "total pollution delivered to the environment", i.e. 20% more wear of something that is 2x as polluting is 40% more pollution. I don't know the numbers or the answer, I'm just saying it's not as simple as your statement makes it out to be.
  - brailsafe 10mo ago
    > 20% more wear of something that is 2x as polluting is 40% more pollution If an equivalent car wore down its tires 20% slower, and those tire particles contributed 2x the intensity of pollution than other types of wear-based pollution, than the increase in produced pollution from that source seems like it would be ~16%, not 40%. If one car drives 100 km and produces 2 units of pollution per km, that would be 200 units. Another car wearing 20% more would produce 240 units, or roughly ~16% more.
    - yunwal 10mo ago
      > Another car wearing 20% more would produce 240 units, or roughly ~16% more. This is some Fermat’s Last Theorem shit
  - coryrc 10mo ago
    Why are you just making up numbers then saying "it's not as simple"? Try educating yourself a little first instead of just jumping to conclusions which reinforce your existing biases.
rcpt 10mo ago
That sounds like a stretch tbh

coryrc 10mo ago

Absolutely. Nearly eliminates. Even non-plugin hybrids have greatly reduced. There was a "study" going around claiming otherwise, which sampled air captured by passing vehicles with a trash bag on a busy road, claiming EVs did not reduce brake dust, but even my brief summary here makes it extremely obvious how flawed this "measurement" is.

margalabargala 10mo ago
For those of us unclear why collecting air from passing cars to measure particulates is obviously flawed, could you elaborate? EVs unfortunately do increase tire particulate, as well. Fairly significantly. It's not obvious to me that the decrease in brake dust isn't made up by the increase in tire dust. The removal of the tailpipe emissions is really where EVs shine from a pollution standpoint. If you turn on your car in your garage, you don't die anymore.
- coryrc 10mo ago
  EV brake pads don't hardly wear down, so they obviously can't have nearly the same amount of brake dust, yet the "study" showed they did. I'm guessing there's brake dust on the ground being kicked up. > EVs unfortunately do increase tire particulate, Fairly significantly In the USA, mass of EV is not significantly different than the alternative choice. EVs do not have increased tire particulate. If in Europe extremely lightweight tiny cars are actually a likely substitution for nicer, heavier EVs, then it seems reasonable that tire wear will increase proportionally. There's a lot riding on that "if" though.
  - margalabargala 10mo ago
    It's not just the fact that EVs are heavier than the non-EV version of the same car, it's also that the regenerative braking means that the tires are dissapating energy that otherwise would have gone to the brake pads or to air resistance. Tires wear way faster on an EV, their lifespan in miles is generally much shorter.
    - 10mo ago

kjkjadksj 10mo ago

You can get this lack of brake pad use with an ice with a manual transmission as well if you engine brake.

shayief 10mo ago
the engine cannot brake to a complete stop, so break pads are always in use. At low RPMs, the engine is going to stall (manual) or switch to neutral (automatic).
- kjkjadksj 10mo ago
  It can brake to nearly a complete stop though with the brakes basically holding the car in place at the end. I got pretty good at it.
- bob1029 10mo ago
  Brake wear scales ~quadratically with vehicle speed. Applying them at 5mph vs 20mph is 16x less energy to burn off.

earlyreturns 10mo ago

I’m guessing not as much as standard transmissions, which largely eliminate the need for breaking while also reducing fuel usage. Yet there are almost no new cars with standard transmission. If only people cared a bit more.

bryanlarsen 10mo ago
You guessed wrong. An electric car can use its engines to bring a vehicle to a complete stop. It can also use the motor to hold the car in place, even on a fairly steep incline. You can't do either with a standard transmission ICE vehicle. There are people with electric cars that have their brakes rust out because they're never used. A standard piece of advice to EV owners is "make sure to use your brakes at least once a month".