Comment by margalabargala
4 hours ago
> but use regenerative braking, which is better for brake dust
Which unfortunately also increases tire wear from regen braking during periods when an ICE vehicle would be coasting without braking.
EVs are much (much much) better for CO2, much better for brake dust, and much worse for tire dust.
Braking from regen or braking from a brake pad has the same net impact on tire wear. EVs can coast too and don’t apply full regen the moment you apply brakes. Some even have brake coach alerts to get you to gradually apply the brakes to maximize energy return.
> EVs can coast too
EVs could coast if a manufacturer chose to make one that allowed that without shifting into neutral. In practice, when letting off the accelerator, existing EVs will instead regen brake.
The default setting just moves the coast point to a slightly depressed accelerator. This is because EVs typically have lower drag, so this behavior mimics a higher drag vehicle. If you use the accelerator to achieve the desired speed, you will coast when possible. You can also monitor the display to see the coast point. My 2013 plug in hybrid only supports this style of operation.
Modern EVs have easy adjustment for this. The Hyundai/Kia EVs for example have shift style paddles for adjusting this on the fly which includes a mode for regen only when depressing the break pedal.
The tires and their dust don't care whether you're braking by regen or friction. The reason there's more dust is from the increased weight of the EV not because of regen braking. You can coast in EV as well, that is not exclusive to ICE.
> The tires and their dust don't care whether you're braking by regen or friction.
I'm aware. The point I'm making is that EVs apply more braking than ICE vehicles do, due to the specifics of the implementation of regen braking that all manufacturers have chosen.
> You can coast in EV as well
Not without literally putting it in neutral. If you just take your foot off the accelerator, any modern EV will apply some amount of regenerative braking. It's not really possible to hold the accelerator pedal at the exact position where you are not applying motor power but also have 0kW of regen braking, certainly for any extended period of time.
If your point is that someone could make an EV to which regen braking contributes no more to tire wear than an ICE vehicle, you're correct. Unfortunately, no such EVs are currently manufactured. Even the ones that allow you to "turn off" regen braking will generally apply 1-2kW of regen if your foot is off the accelerator.
> I'm aware. The point I'm making is that EVs apply more braking than ICE vehicles do, due to the specifics of the implementation of regen braking that all manufacturers have chosen
Hyundai and Kia EVs have a 5 level setting for what happens when you lift up on the accelerator, either partially or fully.
At level 0 the regeneration is so low that I don't notice a difference between that and being in neutral. It slows down way less than an ICE does when not in neutral.
> If you just take your foot off the accelerator, any modern EV will apply some amount of regenerative braking. It's not really possible to hold the accelerator pedal at the exact position where you are not applying motor power but also have 0kW of regen braking, certainly for any extended period of time.
Tire wear is not a linear function of acceleration. Is there any reason to believe that variations from not being able to hold your foot perfectly steady, assuming you aren't have spasms, will be big enough and/or last long enough to make a non-trivial difference?
But ICE vehicles can be in engine breaking mode. You pretty much never "coast" (e.g. put the vehicle in neutral or hold the clutch in). I get what you're saying but it feels like it's way in the margin if an effect at all. Do you have some reference? People keep talking about tire wear but my model 3 tires (which are relatively high performance soft tires) aren't wearing any faster than the wear I used to get on my Subaru before. I just don't drive aggressively. Flooring the accelerator must be the big difference. I don't think the weight difference is that large, certainly compared to trucks.
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I tend to agree with your overall point, but if we're talking about a 1-2 kW of "standby" regen, surely the rolling resistance of any kind of vehicle is in the same ballpark anyway (source: it takes multiple people to push a broken down car).
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