Hacker News Reader

Comment by caseysoftware | Hacker News Reader

As I've cited elsewhere on this thread:

> With that information, the British newspaper calculated that BEVs [battery electric vehicles] could expose roads to 2.24 times more damage than gas cars.

Ref: https://www.autoevolution.com/news/bevs-could-also-damage-ro...

If that's true, then 12-15k miles in an EV would be equivalent to 27-33k miles in a gas car in the externalities of road wear & tear.. so "taxes equivalent to 35k miles" is at most 25% higher in a "damage per mile equivalent" but could be as little as 6% using the averages.

If your actual mileage is over 15625/year, then you're paying less than the equivalent.

What's your annual mileage?

View on HN

27 isn't 35 no matter how many times you say it is.

> If your actual mileage is over 15625/year, then you're paying less than the equivalent.

The average is less than that by a decent bit, so more than half of US cars are paying more even with your unproven, contorted math based on some estimates done once in the 70s and never really looked into closely again.

It's also assuming the difference in weight. The closest hybrid I would have bought instead is only like 100kg lighter than my EV. And it gets like 40mpg, better than 35mpg.

It would also mean semi trucks should pay like 20,000x more in registration fees. Does this make sense?

> What's your annual mileage?

Less than 15k on that car (like most people), so even with your assumed math it's overpaying.

Semi trucks pay huge amounts in gas taxes because they guzzle gas like nobody's business. It's only the EVs that aren't paying for their road wear in gas taxes.

20,000x more in taxes?

Realistically speaking, they probably do. Do you know how much fuel they use and miles they drive per year?

Average class 8 truck (>33,000lbs) burns under 11,000GGEa year, ratio is 1GGE=1.13gal of diesel. So somewhere under 12,500gal of diesel on average, but we'll use that to lean even more in the truck's favor.

https://afdc.energy.gov/data/10308

Are you suggesting the average car burns less than 1 gallon of gas a year?

A 20mpg car driving 12,500mi (the average ICE in the US) would use 625gal of gas. So more like 20x, maybe 40x if the per gallon tax of diesel is double. Pretty dang far off from 20,000x.

And they're doing way more miles while being massively heavier, meaning incredibly more harm on the road than whatever EV you're thinking.

GGE: Gasoline gallon equivalent

<https://en.wikipedia.org/wiki/Gasoline_gallon_equivalent>

(Most tractor-trailor rigs burn diesel rather than petrol.)

12-15k miles in a Ford SuperDuty is equivalent to how far in a gas Civic? I suspect that driver isn't being charged accordingly.

Registration fees are likely the same or close but when you factor in gas taxes (the original comparison here), the Ford is definitely paying more both based on fuel type and mpg.

More, sure. But not remotely proportional to the increased wear and tear from vehicle weight.

Possible. How far off is it?

Pretty far?

According to your link, an EV that is 700lb heavier => 2.24x damage

Civic: ~2900lb SuperDuty: ~5700-7600lb

What is the difference in taxes paid for an equivalent amount of damage?

I understand the point you're trying to make - and you may be right - but you're leaving out the math to demonstrate it.

Civic fuel economy is about 2x an unloaded SuperDuty, so the SuperDuty owner likely pays maybe a bit more than 2x in gas tax + registration.

+700lb (+25%) => 2.25x damage +2800lb (+100%) => ???x damage

Your story doesn't provide a formula, but seems obvious it is much, much greater than 2 - this isn't a linear relationship

And that's the very lightest SuperDuty model, unloaded.

Excellent, much more useful.

Not sure where you are but in Indiana, gas tax for unleaded is 36c while diesel is 62c so on a per-gallon basis, that's an additional +72% in taxes. Back of the envelope: Civic at 30mpg pays 1.2c/mile vs SuperDuty at 15mpg pays 4.13c/mile so the multiple is closer to 3.4 vs 2

So yes - assuming registration fees are comparable and mileage is comparable - the SuperDuty should pay more.

The lightest SuperDuty has a gas engine. Diesel SuperDuty fuel economy is a bit better, but the vehicle also weighs more and is likely to be carrying/pulling more. But regardless of whether the multiple is 2 or 3.4 or somewhere in between, it is a small fraction of the added road wear.

By the fourth power law, an unloaded diesel Superduty creates ~22x the road wear of a honda civic. Loaded can be 100x more.

You keep repeating it, but it's reductive at best and incorrect as a general assumption.

Is there another model you'd recommend to estimate/compare road wear and tear?

1:1 is at least as good a default assumption.

Based on numerous studies, we already know it's not 1:1 so why bother starting with a default assumption that we know is wrong?

Do you have an alternative analysis? I'd love to check it out.

> Based on numerous studies

I do agree the relationship probably isn't linear, but the fourth power rule doesn't necessarily have numerous studies confirming it. It was a small collection of studies on road wear the US highway administration did in the 1950s and pretty much everyone has just gone with that. Other studies have pointed to it being less than previously thought.

https://discovery.ntroknowledge.com.au/discovery/fulldisplay...

Throwing even more weight against your 12,000mi is really 35,000mi equivalence.

Thanks for the insight but my claim was never "12,000mi is really 35,000mi"

Regardless, it would be interesting to see the actual number worked through to see what the equivalent EV registration fee should be if road damage/maintenance is the sole factor.

> If the car was a 35mpg hybrid that would be 35,000mi of equivalent driving.

> that's true, then 12-15k miles in an EV would be equivalent to 27-33k miles in a gas car.. so "taxes equivalent to 35k miles" isn't far off

You absolutely did suggest me paying taxes for 12k miles is practically the same as ~35k miles, you said it several times. That it's not far off. How else am I supposed to read that? You were so sure of it you mentioned it many times.

> Regardless, it would be interesting to see the actual number worked through to see what the equivalent EV registration fee should be if road damage/maintenance is the sole factor.

Sure, but it's likely far less than what I'm paying. As mentioned elsewhere, a similar weight unloaded F-150 pays half the taxes. So I'm at least paying double for similar weight vehicles, and yet you tell me it's really only 6%. But sure, tell me again how I'm really just paying my fair share and 12 = 35.

> If that's true, then 12-15k miles in an EV would be equivalent to 27-33k miles in a gas car in the externalities of road wear & tear.. so "taxes equivalent to 35k miles" is at most 25% higher in a "damage per mile equivalent" but could be as little as 6% using the averages.

^ As you quoted, I used the formula to estimate 12k would be equivalent to 27k and said paying taxes equivalent to be 35k miles is "at most 25% higher", neither of which is "12 = 35". Using their approach, I calculated 35k to be equivalent to 15625 specifically, again, not 12k.

If the underlying approach is wrong, we should replace it with something better.

Alternatively, the OTHER reasoning of "the rich should pay more" still applies, so I assume that's a factor here. Hoping States charge rich people (or high income earners, if you prefer) less isn't likely to work right now.

> Alternatively, the OTHER reasoning of "the rich should pay more" still applies, so I assume that's a factor here.

Once again, your assumption is incorrect. That base model F-150 that pays half the taxes costs more than my EV. The registration fee doesn't factor in income or valuation at all. A $100k Hummer EV pays the same as a $15k used Bolt. Meanwhile that Hummer EV is going to do a hell of a lot more damage to the roads than the Bolt.

It probably has more to do with the government being in the pocket of oil interests and acts accordingly.

I don't agree with your base assumption here.

Reply on news.ycombinator.com