OT: Electric Vehicles--anyone driving them or seriously looked at them?

[cgolvin]

Originally Posted by BdaGhisallo

It found that brakes and tires on EVs release 1,850 times more particle pollution compared to modern tailpipes, which have “efficient” exhaust filters, bringing gas-powered vehicles’ emissions to new lows.

I didn't read the study, but comparing to tailpipe emissions is, to me, misleading. The comparison should be to the aggregation of tailpipe emissions and brake & tire particle pollution produced by ICE vehicles.

Originally Posted by BdaGhisallo

Long story short - EVs are described as zero emission vehicles but they certainly aren't zero pollution vehicles and the pollution they do produce is the kind that can cause real harm to humans.

Don't tailpipe emissions cause real harm to humans?

[BdaGhisallo]

Originally Posted by cgolvin

I didn't read the study, but comparing to tailpipe emissions is, to me, misleading. The comparison should be to the aggregation of tailpipe emissions and brake & tire particle pollution produced by ICE vehicles.



Don't tailpipe emissions cause real harm to humans?

Sure they do, but are the harms of CO2 emissions - the only emission anyone seems to care about these days - as high as those of particulate emissions? I am not so sure. CO2 emissions have some upside but I don't think particulate emissions have any.

[bikinchris]

There is a battery technology in testing right now that has roughly double the capacity of current batteries and charges in roughly 10 minutes. It uses a solid instead of a liquid electrolyte and is based on sodium, not lithium. It is less likely to cause problems if damaged too.

[jimcav]

Originally Posted by BdaGhisallo

Sure they do, but are the harms of CO2 emissions - the only emission anyone seems to care about these days - as high as those of particulate emissions? I am not so sure. CO2 emissions have some upside but I don't think particulate emissions have any.

ICE still have tailpipe emissions besides CO2! VOC's, Black carbon, O3, etc.

They are far better than they used to be, but given the increased number and miles driven they are cumulatively still a significant factor to health--obviously the more urban the environment the worse the impact. There are numerous studies from major urban areas all over the world showing this.

The study cited by emission analytics is now over 4 years old, and even it admitted "Nevertheless, it is important to say that a gentle BEV driver, with the benefit of regenerative braking, can more than cancel out the tire wear emissions from the additional weight of their vehicle, to achieve lower tire wear than an internal combustion engine vehicle driven badly". That doesn't then even begin to take into account that all those ICE vehicles are still emitting more than CO2.

A 2022 study published in The Science of The Total Environment showed "When secondary PM emissions were included, the EF was always significantly lower for the EV than ICEVs. The total PM10 EF of the EV (47.7–57.7 mg/V·km) was lower than those of the gasoline ICEV (56.5–70.5 mg/V·km) and diesel ICEV (58.0–72.0 mg/V·km). Since secondary PM particles are mostly of submicron size, the EFs of the PM2.5 fraction of the ICEVs (28.7–33.0 mg/V·km) were two times higher than those of the EV (13.9–17.4 mg/V·km)". EF=emissions factors.

An even more recent study by SAE in 8/23 showed: "Results for gasoline engine show that a weight increase of 31% and 40% for the hybrid and electric configurations, respectively, with respect to the ICE version, contributes to increase the total PM10 of about 16% and PM2.5 of 9% for PHEV. For BEV, these values amount to 20% for PM10 and to 4% for PM2.5. Adoption of regenerative braking significantly contributes to counteract the effects of a higher weight, so that overall, for PHEV and BEV, total PM emissions are reduced with respect to the ICE versions. In particular, total PM emissions (both PM10 and PM2.5) are reduced of about 3% for PHEV and of 13% for BEV. For the diesel engine, where the weight difference between the ICE and PHEV and BEV versions are more limited (+8% for PHEV and +36% for BEV), higher beneficial effects related to regenerative braking are achieved, so that total PM emissions are reduced of 13% for PHEV and of 14% for BEV, with respect to ICE".

My truck is paid for, and most of my driving is interstate trips to MTB or visit family, but I am very interested in having a vehicle that emits as little as possible. We have solar, so I feel an EV is likely in my near future. I wish there was more hydrogen fuel cell infrastructure in place near me, but there isn't. I do read about potential technologies such as homogeneous charge compression ignition (HCCI) engines, but as yet it is mostly patent filings and not real-world significant changes to current ICE.

[cgolvin]

Thanks for the details @jimcav.

I have to admit, while holding nothing against the authors of the (previously) cited article, anything I read in the WSJ opinion section comes with a healthy dose of skepticism. As much as I respect their news reporters, the bad taste left by the editorials eventually caused me to choose to cancel my subscription (apologies for the slight drift).

[rice rocket]

Originally Posted by BdaGhisallo

The study that brought this to light contrasted the EV particulate pollution to tailpipe emissions from gas powered vehicles. Now, I don't know how the comparison would be to diesel particulate pollution.

Here's the study: https://www.emissionsanalytics.com/n...n-losing-tread

And here's a NY Post article summarizing some of the findings:

https://nypost.com/2024/03/05/busine...ronment-study/

The study, published by emissions data firm Emission Analytics, was released in 2022 but has attracted a wave of attention this week after being cited in a Wall Street Journal op-ed Sunday.

It found that brakes and tires on EVs release 1,850 times more particle pollution compared to modern tailpipes, which have “efficient” exhaust filters, bringing gas-powered vehicles’ emissions to new lows.

Today, most vehicle-related pollution comes from tire wear.

Emission Analytics found that tire wear emissions on half a metric tonne of battery weight in an EV are more than 400 times as great as direct exhaust particulate emissions.

“You have a tradeoff. At the moment, the political agenda is very strong towards climate change reduction. EVs do deliver about a 50% reduction in CO2 — that [affects] climate change.”

“But you have this downside of EVs that increases particle pollution. Air pollution is about what we breathe and the health effects,” Molden said, assuring that the toxins in tires have much less impact on climate change than they do on “what we eat and are ingesting.”

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Long story short - EVs are described as zero emission vehicles but they certainly aren't zero pollution vehicles and the pollution they do produce is the kind that can cause real harm to humans.

Eh. There's a lot of dubious things about that analysis.

Should be pretty simple to compare a regular EV to a regular car, but 9/10ths of the article is comparing to tailpipe emissions. When they finally do get down to the tire wear impact, they beat around the bush and only quote a +500kg, which is a bit of a red herring...that'd mean they're comparing a Model 3 at 3800 lb, to a 2700 lb car (i.e. a Mini Cooper).

[dgauthier]

Originally Posted by BdaGhisallo

(...) Long story short - EVs are described as zero emission vehicles but they certainly aren't zero pollution vehicles and the pollution they do produce is the kind that can cause real harm to humans.

Yes, EV's are hobbled by the fact they're still *cars*. The only solution is to eliminate cars.

Public transportation is the only way to make a meaningful dent in the amount of pollution per person per mile. Maybe then there'd be more room for human powered transportation devices...

[alioup]

EV's are pretty rad, just got my first one at the end of last year and its been great.

I also happen to be a researcher in microplastics/tire wear particles and also sodium-ion batteries. So practice what you preach I guess.

[Black Dog]

Originally Posted by BdaGhisallo

Sure they do, but are the harms of CO2 emissions - the only emission anyone seems to care about these days - as high as those of particulate emissions? I am not so sure. CO2 emissions have some upside but I don't think particulate emissions have any.

So two vehicles of the same mass will not produce the same tire wear particulate pollution if one is an ICE and the other an EV? Another question beyond all the supposed benefits of CO2, is there any other emissions from the tail pipe of an ICE vehicle beyond the CO2 and H2O from the combustion reaction?

[BdaGhisallo]

Originally Posted by Black Dog

So two vehicles of the same mass will not produce the same tire wear particulate pollution if one is an ICE and the other an EV? Another question beyond all the supposed benefits of CO2, is there any other emissions from the tail pipe of an ICE vehicle beyond the CO2 and H2O from the combustion reaction?

Do EVs and ICE vehicles of the same size have the same mass?

[saab2000]

For comparison, My Model Y replaced a VW Tiguan in my garage. They’re both roughly similar in size, have the same seating capacity and similar internal storage volume. From what I can find out through a quick search, my Model Y weighs about 450-500 lbs more than the Tiguan I had. It’s a non-trivial difference but not enormously heavier either. EVs do weigh more, no doubt about it.

The statements above that they wear out brakes more quickly has to be misleading. An EV driver uses the brakes far, far less than on an ICE car due to regenerative braking of the motors. My car’s 1-pedal driving is extremely effective and while I use the brakes, it’s about 90% less than with the Tiguan I had. Can’t comment on the effectiveness of this technology on other brands.

[Black Dog]

Originally Posted by BdaGhisallo

Do EVs and ICE vehicles of the same size have the same mass?

Not at all. However the argument that the ev vehicles produce a vastly disproportionate amount of particulate compared to ice is simply not a sound proposition. Especially when you consider tail pipe particulate and the reduced brake dust from ev due to regenerative braking.

[Louis]

Originally Posted by Black Dog

and the reduced brake dust from ev due to regenerative braking.

Do all / most / some / very few EVs have regenerative braking?

I remember hearing once that it was not universal, and actually inefficient. Not as inefficient as converting all that kinetic energy to heat, but still a technical challenge. However, a quick Google search says that they're about 60-80% efficient, which is pretty good IMO.

[hoj]

Originally Posted by Black Dog

Not at all. However the argument that the ev vehicles produce a vastly disproportionate amount of particulate compared to ice is simply not a sound proposition. Especially when you consider tail pipe particulate and the reduced brake dust from ev due to regenerative braking.

Yeah the regenerative braking makes a huge difference in brake pad wear and tear (in a good way), and it's not only exclusive to EVs.

A lot of hybrids, including the Prius, have had regenerative braking but in my experience the regen braking isn't nearly as noticeable as in a Tesla, for example.

I recently bought a Tesla Model 3 (which is absolutely fantastic), but before that our family owned a 2010 Prius for over 10 years, put over 130,000 miles on it during that time, and changed out the brake pads a whopping total of one time during the entire time we owned that vehicle. I think we swapped them out right around the time our vehicle was approaching it's 100K mile mark.

[cgolvin]

Today at the charging station there was an ID.Buzz charging (no idea why I didn't take a photo, d'oh). Turns out it was a VW employee with a pre-release (domestic) version, so I assume it was LWB but neglected to ask.

Very nice looking!