[apta]

> There's also this ridiculously persistent anti electric vehicle

I'm all for working toward better air quality, and electric vehicles definitely reduce greenhouse (and other) gas emissions. At the same time, pollution from cars is not just from exhaust emissions due to combustion. I recall reading somewhere that 80% or more of particulate matter pollution from cars comes from tires and brakes. So the notion of replacing all combustion engine cars with electric cars will somehow solve the pollution issue is not realistic. The Tesla Cybertruck might be a great vehicle, but it's heavy (large tires and lots of break wear). We need better solutions.

[MayeulC]

As a cyclist, I still find it very hard to breathe when a truck passes me (worst are motor scooters going uphill), and would welcome such a reduction in particulate emissions. I guess that the size of those particulates is not the same either (tires and ICE).

Last article or paper I read on the topic counted particulates drafted from the ground as emissions, which of course EVs do not reduce much. But there's still much less nocive emissions, and doesn't smell as bad...

[davidw]

> We need better solutions.

A good start is fixing our land-use regulation in the US to:

* Allow apartments https://www.sightline.org/2019/11/27/end-apartment-bans-to-s...

* Allow things people need day to day near where they live: https://www.strongtowns.org/journal/2018/2/6/complete-neighb... - if they still have to drive, it won't be as far, and more people will be able to walk and bike.

[fignews]

EVs have regenerative braking. Brake pads last the life of the vehicle.

[thisisnico]

EV's are harder on tires though because of the weight, does it balance out?

[ricw]

Minutely so. Tesla’s model 3 is 200kg (~400 pounds) heavier than BMWs equivalent 3 series. Don’t think the tire wear due to that difference will make much of a difference...

[OnlineGladiator]

400 pounds is a lot, that's more than 10%. The degradation is almost certainly not linear. There is an old study, which admittedly has its flaws, showing road damage was proportional to the fourth (!!!) power of the weight. I don't believe it's that bad (there are very specific conditions for that study and also it does not directly translate to tire wear), but I'd imagine it's at least to the second power, making a roughly 25% difference using your example vehicles.

If someone knows more precise math, please share.

[rtkwe]

That's road degradation though not tire wear...

[polyomino]

https://sci-hub.tw/https://www.researchgate.net/publication/...

If you’re this study posted here before, it was just extrapolating based on weight of ice vehicles and is therefore largely useless in estimating the air quality impact of regenerative braking vehicles.

[hokkos]

"Non-exhaust PM emissions from electric vehicles" study had a Corrigendum because of fake attribution and conflict of interest with a motor component company.

https://www.sciencedirect.com/science/article/pii/S135223101...

> The authors regret that as Victor Timmers did not carry out the research under the auspices of the University of Edinburgh, nor in collaboration or consultation with any personnel at the University of Edinburgh, the affiliation of “University of Edinburgh” has now been removed from this work at the request of the Institution. In addition, subsequent to the publication of the Paper, Victor Timmers has disclosed a potential Conflict of Interest with regard to the work, namely: “non-financial support from Innas B.V, during the conduct of the study”.

Other studies show real benefits https://www.mdpi.com/1996-1073/9/2/84/htm

[OnlineGladiator]

I have no idea about ice, but road degradation is fairly well studied (admittedly I'm learning about it as I find these):

https://higherlogicdownload.s3.amazonaws.com/IPWEA/c7e19de0-...

> For example, a vehicle with an axle weight of 1000 kg is considered to cause 16 times the damage compared with a vehicle with an axle weight of 500 kg.

It seems the 4th power law might actually be more accurate than I thought. If the vehicles can damage the road proportional the fourth power of their weight, surely there is significantly more wear on the wheels (the only part touching the road) than just a linear increase in weight?

My hunch, and again I want someone to provide a more accurate model, is the wear would be proportional the third power of weight.

EDIT: I found something, and it is complicated.

https://journals.sagepub.com/doi/full/10.1177/16878140177000...

Figure 6 is what we're interested in, although you won't understand it without reading everything before it. It's definitely not linear, but it seems to roughly come out to something like the 3rd power, but it really depends (honestly you should click that link, there are so many variables).

EDIT EDIT: Here we go!

https://www.academia.edu/24153619/Tyre_Wear_Model_Validation...

So it seems to be somewhere between the second and third power of weight.

Assuming tire wear is directly proportional to particle emissions (I have no idea if this is true), that would mean (using the 80% of emissions coming from tires number cited in an earlier comment, and EVs being roughly 10% heavier on average) that EVs are actually worse for air quality! This is lumping together brakes and tires though, which could be wrong. Although I am certain there is at least a second power effect from braking from vehicle weight. But as another commenter mentioned, regenerative braking (while not unique to electric vehicles, I think this is a fair contrast) will benefit the EV greatly here. Also it's worth mentioning that while EVs lose, it's not by a huge amount (but it seems to be enough to be measurable).

So like most things, "it's complicated."

[MertsA]

Electric vehicles can use regenerative braking for the majority of the time in normal driving. Brake pads can last substantially longer on hybrids and electric cars because of this.

[wasdfff]

With stick shift cars you can use the engine to brake and get the same brake pad savings

[mikestew]

...at the expense of piston rings and other expensive, hard-to-get-to items. And, an educated guess here, probably increased emissions on the overrun.

Besides, who drives stick anymore? I've driven stick since I learned to drive forty years ago, and I even I admit that I can't do better than a computer-controlled DCT, on performance or fuel efficiency. Next car is either electric (we already have a Leaf), or DCT if we must.

[RcouF1uZ4gsC]

> ...at the expense of piston rings and other expensive, hard-to-get-to items. And, an educated guess here, probably increased emissions on the overrun.

This seems like a bad tradeoff. Increasing wear on expensive, hard to replace parts (your engine and transmission), so that you can save on relatively inexpensive, easy to replace parts (your brake pads)

[inferiorhuman]

This seems like a bad tradeoff. Increasing wear on expensive, hard to replace parts (your engine and transmission), so that you can save on relatively inexpensive, easy to replace parts (your brake pads)

So that's not actually the tradeoff you're making. More to the point you run a much higher risk of acute failure with brakes than with anything else. When that happens on a downgrade you can't stop. If you were actually increasing wear on piston rings (a laughable argument at best) you might end up needing to rebuild the engine after a few decades.

[kovach]

There are no fuel emissions when you engine brake in a modern fuel injection vehicle, as fuel intake is stopped [1].

But it could be bad for your piston rings and catalytic converter [2], so there's that...

[1] https://en.wikipedia.org/wiki/Engine_braking#Gasoline_engine...

[2] https://ricksfreeautorepairadvice.com/engine-braking-cause-d...

[inferiorhuman]

Good lord Rick's Free Auto Repair Advice is worth what you paid for it. Compression brakes (of which Jacobs is one brand) actually do increase top end wear on a diesel quite a bit. What Rick is prattling on about might have been an issue in the 60s when engines would be well worn by 100,000 miles and PCV was not a thing. These days you're sucking crankcase gasses right into the combustion chamber constantly thanks to what's known as positive crankcase ventilation. Typically when you see a puff of smoke after overrun that's an indication of bad valve guides more than anything else (also not a common occurrence these days).

Oil in your catalytic converter isn't good, but that's why you have one or more spark plugs per cylinder — to burn it. There's the issue of heavy metals in the oil (e.g. zinc – generally in the form of ZDDP) that can damage your cat, sure, but that's why the current API specs have reduced the amount of allowable zinc a revision or so ago (API SN or SM I believe). Zinc is a great anti-wear additive but in high enough concentration can damage your cat.

Stop and go traffic will wear your clutch out (assuming we're talking cars with dry plate clutches here and not a motorcycle or anything else with a wet clutch). Engine braking will not (assuming you're not riding the brakes or constantly shifting while trying to slow down). Hell, even if you are downshifting needlessly if you're rev matching you're not wearing the clutch all that much. I'll take this fictitious clutch wear over acute brake failure thank you very much. In fact I've yet to destroy a cat or clutch in San Francisco traffic.

[inferiorhuman]

...at the expense of piston rings and other expensive, hard-to-get-to items.

Uh, no.

And, an educated guess here, probably increased emissions on the overrun.

Also, no. Most cars built in the last 30+ years will stop injecting fuel during overrun.

[thfuran]

You can but very few people drive stick in the US and, of those, I suspect very few use engine breaking for a significant fraction of their braking. For getting off a highway maybe, but probably not for stop and go in a city.

[paulie_a]

In fact engine breaking is illegal in most populated areas

[jandrese]

This is not true. There are specific areas that ban it and have signage alerting drivers to that fact, but it is not common.

Plus, it typically only applies to Semis as their engine braking is especially noisy. On a typical gas powered sedan you would be hard pressed to identify that someone is engine braking unless you were right next to it. Being prosecuted for it would be even more exceptional.

[organsnyder]

That kind of engine braking (the kind trucks do that's extremely loud) is completely different from "engine braking" with the transmission

[macintux]

This is the braking that communities post signage about: https://en.wikipedia.org/wiki/Compression_release_engine_bra...

[PeterStuer]

Or just use the Cruise Control speed toggle on your automatic. At least on mine (BMW) it engages regenerative breaking when you click down the speed.