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Aptera's First Solar Road Trip. 300 Miles, One Charge

(aptera.us)
49 points geox | 5 comments | 31 Mar 25 11:05 UTC | HN request time: 1.012s | source
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dontlaugh ◴[03 Apr 25 07:20 UTC] No.43566006[source]▶
Focusing on efficiency is a good idea, but why is it so big? It’s silly that it’s over 4m long.
replies(2): >>43566757 #>>43567156 #
_ph_ ◴[03 Apr 25 09:36 UTC] No.43567156[source]▶
Because it needs to be that long to have a low air resistance. There are two determining factors for air resistance. First, the cross section A, which determines the amount of air to be moved and second the drag coefficient c, which describes how well the air flows around an object. This gets lower the more "round" a shape is, but the sphere isn't actually the best one, you want the form of a falling raindrop. For that the shape needs to be quite a bit longer than it is wide. So if your car is e.g. 2m across, it needs to be something like 4m long to approach best efficiency. See also the empty "tails" attached to some racing cars for drag reduction.
replies(1): >>43567178 #
1. dontlaugh ◴[03 Apr 25 09:40 UTC] No.43567178[source]▶
They could either make it narrower or slightly less efficient.

That length makes it too big in many countries, especially for just two seats.

replies(1): >>43567233 #
2. _ph_ ◴[03 Apr 25 09:49 UTC] No.43567233[source]▶
I think it is already as narrow as you can put 2 seats side by side. But then indeed it becomes a tradeoff between size and efficiency. They went for maximum efficiency. And it is still 26cm shorter than a Model 3. So while not an compact car, not overly large either.
replies(1): >>43567259 #
3. dontlaugh ◴[03 Apr 25 09:52 UTC] No.43567259[source]▶
You’re comparing against a car that is difficult to use on UK roads due to its length and (to a lesser extent) width. Perhaps in the US it’s not that big, but here it is.
replies(1): >>43567598 #
4. anentropic ◴[03 Apr 25 10:36 UTC] No.43567598{3}[source]▶
You can't be serious that the length of a Model 3 makes it difficult to use on UK roads? It is a typical mid size vehicle, there are loads of vehicles of this size and larger on the roads over here.
replies(1): >>43567727 #
5. dontlaugh ◴[03 Apr 25 10:50 UTC] No.43567727{4}[source]▶
There are definitely cars that size and bigger and I frequently see their drivers struggle to park or navigate narrow roads.

I'd call something like a Golf/Focus "mid size". There's approximately two sizes below and two sizes above.