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by amelius 1249 days ago
And their increased weight makes them much harsher on roads than normal cars. They wear down roads faster, and I suppose they also produces more particle pollution than normal car for this reason.
3 comments

Threads like this read like EVs are double or more the weight of an ICE car.

EVs are a couple hundred pounds heavier in average than an equivalent ICE car. In terms of road wear, it's still a rounding error compared to industrial trucks.

The road wear is said to be proportional to the fourth power of axle load. http://www.cyclelicio.us/2014/fourth-power-rule-road-tax/

That means you deal twice the damage by increasing weight by only 20%. Seems in line with electric car weight difference.

Yeah, that's my point. A single garbage truck is going to do more wear on the roads than thousands of passenger vehicles. Anything besides industrial vehicles is negligible.
A garbage truck has many tires to distribute the load. Also they accelerate/decelerate differently.
The rear tandems of a semi or heavier straight truck (garbage truck, dump truck, etc) occupy roughly the same road area as your car and may be carrying the weight of ~10x your car. The contact pressure is also much higher (100+psi tires vs your 20-40 or so).
Per OP's report, what matters is axle load.

A typical garbage truck has 2 or 3 axles. Let's assume 3 to be conservative. A fully loaded garbage truck weighs around 50,000 pounds. That's 16.6k pounds per axle, vs a Tesla Y's 2.2k pounds per axle.

Doing the math, a single garbage truck does as much road wear as ~3,300 teslas.

Yeah turns out an electric drive train is much lighter than a gasoline one which offsets the battery weight somewhat. Gasoline engines aren't light, nor are the transmissions. Currently I think the weigh penalty is about 15-20%.

My guesstimate is if they can increase the energy density of batteries by 30-50% the weight penalty will disappear. Some of the reduction is the weight reduction of the battery and some is due to cascading effects on the rest of the car.

"couple of pounds heavier"??!?! That's understating it.

Seriously, a Model 3 is ~500 lbs heavier than Honda Accord, and a Model Y is significantly heavier than a Model 3.

Typo, fixed. I could have sworn I typed "couple hundred pounds".

But to your point, a bmw 430 is also around 500 pounds heavier than a Honda Accord. Nobody sees a BMW and freaks out about tire wear. But people seem to hyperfixate on any small negative of EVs.

> But to your point, a bmw 430 is also around 500 pounds heavier than a Honda Accord.

At the heaviest weights, yes, but the heaviest Accord weight and the lightest 430i weight are only 148 lbs apart... and the Model Y can weigh in almost 400 lbs heavier than the heaviest of 430i's.

> Nobody sees a BMW and freaks out about tire wear.

You mean, so long as it's not an EV? ;-)

Seriously, nobody freaks out about a BMW 430i's tire wear, because that of the branding of the car. It's like freaking out over coffee increasing your heart rate.

> But people seem to hyperfixate on any small negative of EVs.

We're obviously talking to different people. At least the folks I know talk about how crazy heavier cars keep getting across the board (case in point: https://www.capitalone.com/cars/learn/finding-the-right-car/...).

Be fair, those aren't comparable cars. BMW Model 3 and the Tesla model 3 are pretty similar in size, weight, and cost. The fastest of both is AWD and the Tesla is 4072 pounds and the M3 Competition and M3 Touring (the 2 variants with AWD) are 3924 pounds to 4116.

The non performance models are similar as well, the current BMW 3141-4023 pounds (the AWD are of course on the heavier side, and the Tesla model 3 is 3814 pounds.

Because of the weight scaling characteristics (damage done corresponds to fourth power of axle weight), it’s irrelevant if trucks are allowed on the same roads. The damage increase done by EVs is probably not even worth considering.
Any light vehicle traffic is basically inconsequential for any road build to handle any amount of medium trucks or heavy trucks.

Complaining about the 9000lb EV hummer makes for some great circle jerks among the demographics that hate people who drive normal hummers but the road basically doesn't care about them.