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Air pollution fell substantially as Paris restricted car traffic

washingtonpost.com

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Re: Air pollution fell substantially as Paris restricted car traffic

#71

Post by trollbridge »

lotsofpulp wrote: post #70
trollbridge wrote: post #64

Earlier quoted context omitted.

But spews forth more rubber (and plastic, since that's what tyres are made from these days), which is an ongoing problem for Tesla EVs when owners discover their tyres don't last nearly as long because they're transmitting power both when starting and stopping, not just when starting.

I don’t understand this concept. I would expect an ICE and an EV vehicle with the same weight, speed, deceleration, tires, etc to have the same wear on tires. The difference being the energy to stop an ICE being transferred to the brake pads and rotors, rather than recharging the EV’s battery. What am I missing? Why wouldn’t the tires experience the same forces in both scenarios?

It's due to the regenerative braking, which transmits more power via the wheels when decelerating. Most ICE cards don't have regenerative braking; hybrids tend to.

Re: Air pollution fell substantially as Paris restricted car traffic

#72

Post by detaro »

trollbridge wrote: post #64
dmckeon wrote: post #27

Earlier quoted context omitted.

Regenerative braking would tend to reduce particulates from friction braking.

But spews forth more rubber (and plastic, since that's what tyres are made from these days), which is an ongoing problem for Tesla EVs when owners discover their tyres don't last nearly as long because they're transmitting power both when starting and stopping, not just when starting.

> because they're transmitting power both when starting and stopping, not just when starting.

For the tires it doesn't matter if the energy from stopping is transferred into brakes or back into a motor though?

Re: Air pollution fell substantially as Paris restricted car traffic

#73

Post by bri3d »

trollbridge wrote: post #71
lotsofpulp wrote: post #70

Earlier quoted context omitted.

I don’t understand this concept. I would expect an ICE and an EV vehicle with the same weight, speed, deceleration, tires, etc to have the same wear on tires. The difference being the energy to stop an ICE being transferred to the brake pads and rotors, rather than recharging the EV’s battery. What am I missing? Why wouldn’t the tires experience the same forces in both scenarios?

It's due to the regenerative braking, which transmits more power via the wheels when decelerating. Most ICE cards don't have regenerative braking; hybrids tend to.

This doesn't make sense. Energy in the system is conserved. On an ICE car, brakes convert the energy to heat. On an EV, motors convert the energy to electricity. The tires experience the same net force.

EVs wear tires more quickly, in general, because they are very heavy and produce more torque (and drivers are more likely to request that torque, also).

Re: Air pollution fell substantially as Paris restricted car traffic

#74

Post by [deleted] »

trollbridge wrote: post #64
dmckeon wrote: post #27

Earlier quoted context omitted.

Regenerative braking would tend to reduce particulates from friction braking.

But spews forth more rubber (and plastic, since that's what tyres are made from these days), which is an ongoing problem for Tesla EVs when owners discover their tyres don't last nearly as long because they're transmitting power both when starting and stopping, not just when starting.

[deleted]

Re: Air pollution fell substantially as Paris restricted car traffic

#75

Post by [deleted] »

trollbridge wrote: post #71
lotsofpulp wrote: post #70

Earlier quoted context omitted.

I don’t understand this concept. I would expect an ICE and an EV vehicle with the same weight, speed, deceleration, tires, etc to have the same wear on tires. The difference being the energy to stop an ICE being transferred to the brake pads and rotors, rather than recharging the EV’s battery. What am I missing? Why wouldn’t the tires experience the same forces in both scenarios?

It's due to the regenerative braking, which transmits more power via the wheels when decelerating. Most ICE cards don't have regenerative braking; hybrids tend to.

[deleted]

Re: Air pollution fell substantially as Paris restricted car traffic

#76

Post by microtonal »

stavros wrote: post #63
pama wrote: post #45

Earlier quoted context omitted.

In modern cars, including EV, polution and noise come from weight and tires and breaks; the polution levels are a sharp funxtion of speed, but the speeds at which they dont matter much, dont offer benefits either. If we had magnetic/levitated cars maybe some simple solution could be found, but with the current designs where the tires hit the asphalt it seems hard to make things environmentally friendly in a city othe…

This is a bad-faith fallacy. We had cars that emitted X amounts of tyre/brake particulate and 10X amounts of combustion residue, we got rid of the combustion part, and now we hear "OMG! 100% is tyre particulate!!!" Sure, but people won't stop moving, and there's no vacuum, you should compare brake particulate to whatever else people would use if cars didn't exist.

Or you could just make a city car-free. There are so many benefits besides fewer particles in the air. People can walk and cycle safely. Kids can play in the streets. The atmosphere is so much nicer, since people are not isolated by walls around them.

I have lived in a city with a (nearly) car-free city center (+ separate bike lines for many roads outside the center) for most of my adult life [1] and it is just glorious. Most locals just walk or cycle. Longer distances by (electric) bus or train.

[1] https://en.wikipedia.org/wiki/Groningen#Cycling_and_walking

Re: Air pollution fell substantially as Paris restricted car traffic

#77

Post by epolanski »

grg0 wrote: post #31

Cars in cities, let alone designing cities around cars, is one of the greatest tragedies of modern life.

And it's one of the biggest promoters of inequality.

I am an European who studied at OSU in Columbus for a semester and it was absurd to me how on one side there was lots of work downtown, yet you could live 20 miles of it and it would take you two hours by public transport to get there, an odyssey.

People without a car, insurance, poorer parts of the society were cut off from the job market for not having a way to connect.

Suburbs are cute, but they are a tragedy of city planning, let alone the tragedy they are on a social level, where people will put everything in their houses including movie rooms, entertainment rooms, anything to avoid having to go out and socialize. Terrible.

Re: Air pollution fell substantially as Paris restricted car traffic

#79

Post by lotsofpulp »

trollbridge wrote: post #71
lotsofpulp wrote: post #70

Earlier quoted context omitted.

I don’t understand this concept. I would expect an ICE and an EV vehicle with the same weight, speed, deceleration, tires, etc to have the same wear on tires. The difference being the energy to stop an ICE being transferred to the brake pads and rotors, rather than recharging the EV’s battery. What am I missing? Why wouldn’t the tires experience the same forces in both scenarios?

It's due to the regenerative braking, which transmits more power via the wheels when decelerating. Most ICE cards don't have regenerative braking; hybrids tend to.

If the stopping distance is the same (same accel/decel), I don’t understand this statement

> because they're transmitting power both when starting and stopping, not just when starting.

bri3d’s adjacent post is what my thoughts would be on why EV’s consume more tires.

Re: Air pollution fell substantially as Paris restricted car traffic

#80

Post by epolanski »

bri3d wrote: post #12

Worth noting that 50-60% of passenger cars in France are diesel, but Paris have been gradually banning older higher emission diesels (Crit’air 3, 4, 5) from Paris. Banning cars outright also works, of course, but I suspect a lot of the reduction can be attributed to getting particularly bad diesel cars out vs. the limited areas where cars are entirely restricted.

I lived in downtown Rome, Italy. By far the biggest pollution you get in your house, it's...dust from brakes. It's a tragedy.

Not saying diesel ain't bad, but even now that diesels have been largely banned or reduced to euro 6, it has changed nothing about brake dust.

My flat would fill with it in a single day. It's everywhere. And I lived on a third floor, not even at street level.

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