5 ms·

What is the cause of that ~30%?

• nkingsy 6y ago
  Brakes/tires
  • karakot 6y ago
    it's nowhere close to true. otherwise you'd have to change your tires and brakes each time you visit a gas station.
    • Fezzik 6y ago
      It may be you who are mistaken: “...particles from brake wear, tyre wear and road surface wear directly contribute to well over half of particle pollution from road transport.” https://www.bbc.co.uk/news/business-48944561 https://www.bbc.co.uk/news/business-48944561
      • trickstra 6y ago
        Notice how they specified "particle" pollution. That's a subclass of the general pollution. Small subclass.
        • Fezzik 6y ago
          Particle pollution, if they are using it correctly, which I think they are, includes exhaust and pretty much every post-production pollutant produced by a car (before it is scrapped I guess). See: https://www.epa.gov/pmcourse/what-particle-pollution https://www.epa.gov/pmcourse/what-particle-pollution
      • karakot 6y ago
        Or you can use some basic math, and calculate how much tire/breaks wears(loses original matter) per 100 000 km and how mach of gas a car burns for the same distance and compare these numbers.
        • emj 6y ago
          I would guess that gasoline must result in mostly heat and not particle pollution in PM10 and PM2.5.
          • karakot 6y ago
            https://en.m.wikipedia.org/wiki/Conservation_of_mass https://en.m.wikipedia.org/wiki/Conservation_of_mass
            • Fezzik 6y ago
              That does not tell us anything though. The fact is that “The largest part of most combustion gas is nitrogen (N2), water vapor (H2O) (except with pure-carbon fuels), and carbon dioxide (CO2) (except for fuels without carbon); these are not toxic or noxious (although water vapor and carbon dioxide are greenhouse gases that contribute to global warming). A relatively small part of combustion gas is undesirable, noxious, or toxic substances, such as carbon monoxide (CO) from incomplete combustion, hydrocarbons (properly indicated as CxHy, but typically shown simply as "HC" on emissions-test slips) from unburnt fuel, nitrogen oxides (NOx) from excessive combustion temperatures, and particulate matter (mostly soot).” Emphasis added. https://en.m.wikipedia.org/wiki/Exhaust_gas https://en.m.wikipedia.org/wiki/Exhaust_gas
          • Gibbon1 6y ago
            What happens is you can never get fully complete combustion. Some of the gasoline gets cracked and recombines to form HC soot. Which is also very reactive. Thus likely really bad for you. https://www.bts.gov/content/estimated-national-average-vehicle-emissions-rates-vehicle-vehicle-type-using-gasoline-and https://www.bts.gov/content/estimated-national-average-vehic... This gives actual figures for PM2.5 emissions from exhaust, brake wear, and tire wear per mile for both gasoline and diesel vehicles. There is an argument about how much EV's would reduce PM2.5. The above shows things were a lot worse 20 years ago. And current gasoline cars produce 0.008gm/mile PM2.5 from exhaust and 0.003 and 0.001 from brakes and tire wear. That says to me that EV would still reduce emissions a lot. One can assume that brake wear is half that of a gasoline powered car. So you go from 0.011gm/mile for gas. To probably 0.003 for EV's. Electrifying diesel trucks is a huge win.
    • nkingsy 6y ago
      A lot of energy has gone into cleaning up engine pollution already. Not sure where the 30% number comes from, but Brakes probably will get cleaned up once they become the star of the show.
      • pmorici 6y ago
        EVs already solve that problem by mostly eliminating use of brake pads with regenerative breaking.