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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 b

• margalabargala 11mo 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.
  • barnabee 11mo ago
    > 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 This does not seem correct... - Air resistance slows the car without putting anything extra through the tyres (the friction is between car and air rather than between tyre and road) - Regenerative braking channels energy into the battery, and also heat, that would otherwise be dissipated by heating and ablating the brake pads and discs, but regardless or whether it's brakes or the the motor acting as a dynamo that puts resistance on the rolling of the wheels, for a given amount of braking you will have the same forces between the tyres and the road and the same tyre wear. So I'd expect it's only any additional weight that contributes to increase tyre particulates from electric care. Perhaps a tiny contribution from lower air resistance (on average at least) for electric cars, as there's often quite an effort to reduce the drag coefficient for range reasons, but I wouldn't expect this to be substantial as air resistance is not huge part of braking.
    • margalabargala 10mo ago
      Regenerative braking needs something to act against in order to slow the car down. Whether the thing on the car side is an electric motor generating voltage or a brake caliper generating heat, the effect of both is to create resistance to the axle turning. This slows the car via tire-road friction. EVs tend to use regenerative braking, thus applying road-tire friction, much more often than an ICE vehicle uses brakes. In an EV if you are going tobfast and let off the accelerator, the regen braking slows you. With tires. In an ICE car, you will coast along and slowly slow down, mainly due to air resistance, unless you actively press the brake. If regen braking only happened when then EV driver pushes the brake pedal with their foot, your expectations would be correct and weight would be the only differentiator. But the single pedal driving design decision means the tires wear more.
      • vladvasiliu 10mo ago
        But if the car decelerates harder when you let off the gas than you expect (compared to an ICE), maybe you'll give it a bit more "gas", so that, in the end, your deceleration is roughly the same in both types of cars? I haven't noticed EVs oscillating between full acceleration and hard braking when out and about. They seem to be driven pretty much the same as any other car. If I'm not mistaken, this means that tyre wear should be roughly equivalent (for an equivalent vehichle weight). So EVs still have the benefit of reducing brake pad wear.
        • margalabargala 10mo ago
          The oscillation you mention does exist, it's just small enough that it's tough to pick out visually watching the car. But it can be felt within the vehicle, and the small oscillations are certainly enough to wear tires more than the ICE alternative. If you have any friends with motion sickness, ask them if it feels different to be a passenger in an EV. Alternately go to a tire shop and ask whether EVs wear tires faster. All this isn't to say EVs aren't better than ICE vehicles. They are, in many ways. It's just that tire wear isn't one of them.
  • bryanlarsen 11mo ago
    The engines are absorbing the energy that would have otherwise gone to the brake pads. Tires apply the braking force to the ground in exactly the same manner on both EVs and ICE vehicles.
    • margalabargala 10mo ago
      Firstly, the motors absorb half the energy. The other half goes to the tires. It would be great and efficient if the motors could.absorb it all but unfortunately physics doesn't work that way. Secondly, if you've ridden in an EV, you would know that the drivers/cruise control often apply regent braking in situations where an ICE vehicle would have simply coasted to a stop. Hence more wear.
      • two_handfuls 10mo ago
        The tires wear the same amount here because either way, the car decelerates by the same amount at roughly the same rate.
        • margalabargala 10mo ago
          No, it doesn't. With the ICE car, if you want to go 55, you might accelerate to 57 and then coast down to 55 without using brakes. With an EV you might accelerate to 57 and then brake to 55 when you let off the accelerator. Tire wear is a function of how often you use your tires to slow down the car. With an ICE car that's every time you hit your brakes. With an EV that's both brakes and regen. An EV's time spent braking or regenning is more than the time an ICE car spends braking. Someone could design an EV that behaves the way you describe, but aggressive regen sells better, so no one does.
          • two_handfuls 10mo ago
            Coasting wears your tires too. By the same amount.
            • 10mo ago