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by thisisnico 2387 days ago
EV's are harder on tires though because of the weight, does it balance out?
1 comments

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...
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.

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

"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

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."

(For anyone unaware, in this context "ice" most likely refers to "internal combustion engine" vehicles.)