Mythbusting the world of EVs: do heavy EVs cause bad air quality?

Myth: Heavy EVs cause bad air quality

There’s been a lot of noise lately that EVs, because they’re heavier than ICE cars, wear out their brakes and tyres faster. And tyre and brake pad particulates are like exhaust particulates – very bad for health.

But in cities, where the people are breathing the air and where they’re closer to the traffic, vehicles move slowly and hardly wear their tyres. So tyre particulate emissions matter less than on faster roads – at least from the point of view of lung health. And brakes? EVs hardly use their brakes, because most of the slowing down is done by the motor, in regeneration.

So, in places where the biggest number of people are breathing the biggest amount of poisoned air, EVs definitely help. In short they remove from the equation tailpipes that squirt particulates at the height of the nostrils of toddlers in pushchairs.

The tyre thing is less well understood right now. But think: a brand new car is allowed to put out 4.5mg of particulates from its exhaust per km. Over 30,000km that’s 135g. I pick that distance because it’s the typical length of a tyre’s life, during which your tyres will lose maybe 4kg of rubber between them – 30 times as much as the exhaust. We just don’t know where that goes – air? Soil? Drains? All bad things.

But crucially there is little evidence that EV tyre life is less than those on increasingly heavy combustion cars.