Urban Legend?

Aptera Community Aptera Discussions Urban Legend?

Aptera Community Aptera Discussions Urban Legend?

  • Urban Legend?

     Dennis Swaney updated 1 week, 1 day ago 12 Members · 21 Posts
  • Donald Borger

    Member
    September 19, 2022 at 1:02 pm

    It’s been going around that the Aptera has less wind resistance than one of the mirrors of an F-150. Is that a fact or just wishful thinking?

  • Joshua Rosen

    Member
    September 19, 2022 at 1:20 pm

    Chris Anthony keeps saying this, it might be an exaggeration. He also keeps saying that the average EV uses 400Wh/mile, I don’t know where he got that figure. The vast majority of EVs on American roads are Teslas, the Model 3 is about 240Wh and the Model Y is a tiny bit more. The other EVs that have sold significant numbers like the Bolt and the Leaf have similar numbers. Ford will have to deliver a hell of a lot more Lightnings then they have to push the number up to 400Wh.

  • Curtis Cibinel

    Member
    September 19, 2022 at 1:24 pm

    Perhaps not now with the losses from the adding of mirrors (thanks NHTSA) but Aptera did say this frequently in the Alpha/Beta stages.

    • kerbe2705

      Member
      September 19, 2022 at 6:48 pm

      @Curtis Cibinel Chris has repeatedly stated that Gamma’s CD had improved upon Alpha’s predicted CD of .13 – so my hope is that, however much that improvement is, the side mirrors might negate it without raising the CD above .13.

    • George Hughes

      Member
      September 19, 2022 at 8:09 pm

      Do consider the mirror part is designed to be removed with the side rear view camera left in operation. If you remove them you will give the police a reason to pull you over if they notice.

      Nine times out of ten if you have them on hand you will be able to talk yourself into a verbal warning with the defender of peace being more intrigued by the Aptera than writing you up.

      I expect when Aptera is generally available, some one will make a video about the real world impact at 70 mph with and without the mirrors.

      • kerbe2705

        Member
        September 19, 2022 at 9:51 pm

        @George Hughes The mirror/camera units on the Gamma are one-piece: I have a feeling that removing them – when the US laws change – might be more about replacing than removing. My guess is that the camera will pop out of the mirror housing and pop into an aero camera housing.

        • Sam Adams

          Member
          September 20, 2022 at 5:21 am

          The camera is actually the primary build. And the mirrors are attached to them for easy removal.

          • kerbe2705

            Member
            September 20, 2022 at 10:13 pm

            @Sam Adams – the Gamma mirror/camera is of an entirely different design than the camera “wing” on the Alphas. Multiple videos and photos of Gamma show the mirror/camera to be a one-piece unit. Whatever might be installed eventually, they are currently NOT a mirror attached to a camera.

            • Sam Adams

              Member
              September 21, 2022 at 7:13 am

              Trying to find that video from fully charged is like looking for a needle in a haystack stack. It could be possible that Chris was referring to Delta, I suppose.

            • OZ (It’s OZ, Just OZ)

              Member
              September 21, 2022 at 11:21 am

              I’m with Sam here Kirby, I haven’t seen it in person, and it’s quite possible as well that this is something they put together quickly for the show. But from CA’s description of what to expect, it would make sense to have the camera mounted close in (As what appears to be the lens in the pictures I’ve seen is.) and the outer portion with the physical mirror designed to slip over that, leaving the lens exposed and secured in place, but easily removeable.

            • Dennis Swaney

              Member
              September 21, 2022 at 12:41 pm

              Agree. However, what CA says and what actually appears seem to be out-of-sync. I get the feeling that he is more PR and the actual designers/engineers are doing what they need to do regardless of some statements by him. That might be why they are so lacking in true openness and still have made the major decision about the body material (a decision that should have been locked down several months ago. Also, Alain’s concerns on the very poor workmanship of the Gamma’s solar cells and connections may be related to the lack of a decision on the body. So perhaps the cameras/mirrors are also related, with the Gamma versions being just a slap-dash construction for the show.

            • George Hughes

              Member
              September 21, 2022 at 1:48 pm

              But Dennis … what they need to do is make the ‘obsolete’ mirror part replaceable because … well I’ve replaced a couple of outboard mirrors over the years. I suspect if we look at the bottom of the outboard mirror assembly you’d see a fastener as the mirror fits over the camera assembly. If it were not able to be separated, you’d have to replace the camera too and that doesn’t make sense for a body part that is so apt to damage.

              I certainly don’t think they are so concerned about long-term compliance of the part with regulations that are in the queue for imminent change that they intentionally chose to make a design to defeat non-compliance. Given the repair angle, the notion that they couldn’t, for regulatory compliance, make the mirror portion replaceable without replacing the entire item would be ludicrous.

              However, if they did, it would be the most stupid design choice I’ve seen them make. I just don’t believe they’d make that choice.

            • Dennis Swaney

              Member
              September 21, 2022 at 6:16 pm

              That is a good point, George. Hopefully the mirrors on the Gamma are two piece with the joint very cleverly hidden even though they aren’t mounted on a composite that won’t be used in the production version body.

              As an absolute minimum the right side mirror will be removed on the vehicle I get, and most likely the left side later down the road.

  • kerbe2705

    Member
    September 19, 2022 at 6:45 pm

    @Donald Borger The claim is based on this SAE test – which found that pickup truck side mirrors have a CD of 1.81. BTW, the CD of a brick is .82…

    https://www.sae.org/publications/technical-papers/content/920204/

    • Curtis Cibinel

      Member
      September 19, 2022 at 8:04 pm

      Regardless of EV or ICE the wasted energy from mirrors is ludicrous. ~3-5% loss from mirrors is typical for cars so cameras would save a massive amount of energy or fuel. The potential environmental impact is substantial.

      • kerbe2705

        Member
        September 19, 2022 at 9:52 pm

        @Curtis Cibinel Every little bit helps!

  • Francis Giroux

    Member
    September 20, 2022 at 10:58 am

    Concerning the F150 mirror drag vs Aptera drag let’s look into it.

    Comparing the drag on each vehicle will be assuming they are going the same speed so we can leave that out of the drag equation for comparison sake. What we will compare is frontal surface area times drag coefficient. According to this site https://aptera.nu/?p=67

    Unfortunately Aptera hasn’t published the frontal surface area. I have however found two sources for the product of Cd and A. In this online calculator it lists the Aptera 3 (the current design) with a Cd*A of 0.27 m<sup style=”font-family: inherit; letter-spacing: 0px;”>2</sup>, or 2.94 ft<sup style=”font-family: inherit; letter-spacing: 0px;”>2</sup>. Assuming the Cd = 0.13 was correct, this would indicate an effective frontal surface of 2.1 m<sup style=”font-family: inherit; letter-spacing: 0px;”>2</sup> or 22.6 ft<sup style=”font-family: inherit; letter-spacing: 0px;”>2</sup>.”

    We will use this as relatively dependable. Now for the Ford F150 mirror: according to NASA at

    https://www.grc.nasa.gov/www/k-12/airplane/shaped.html the Coefficient of drag of a flat plate would be 1.28 and according to Google the F150 mirror dimensions are 18.2 inches by 14.1 inches not counting the brackets holding it to the truck. That is 1.78 square feet for the mirror alone. Multiply that by the coefficient of drag of a flat plate (1.28) and you get 2.281 drag square feet. By the time you add the sizes and drag coefficients of the brackets holding the mirror to the truck, certainly you could justify the .66 Drag square feet difference between the Aptera vs the Mirror alone on the F150.

    Maybe the dimensions and shape of the F150 used here are for an older F150 ( pre 1996). I think they may have improved their aerodynamics in more recent models.

    Chris may have been thinking of the older trucks when he got into the habit of making the comparison between the drag of the entire Aptera versus the Drag of one mirror on a F150 pickup truck. But as long as there is at least one of those trucks on the road, he’s not wrong.

    • John Trotter

      Moderator
      September 20, 2022 at 6:59 pm

      Francis Giroux. Nice work. My only nit would be I would assume Ford designers are not idiots and have better mirror aerodynamics than a flat plate. But, who knows for sure??

      • Paul Kirchner

        Member
        September 20, 2022 at 7:31 pm

        I think they’re more concerned about making the trucks appear as macho as they can. Bulging muscular fenders, bulging hood, oversized logos, massive flat sided front. They have to appeal to vain male ego more than anything else.

    • kerbe2705

      Member
      September 20, 2022 at 10:15 pm
    • Michael Marsden

      Member
      September 21, 2022 at 2:01 am

      This.

      At the end of the day, the important measurement is CdA not Cd. A coefficient of drag of a single component on its own is meaningless. You might as well say that the CD of the Lightning’s bed is lower than the CD of Aptera’s seats, but that would obviously be a silly way to compare them.

      Pretty sure that the CdA of the Aptera vehicle as a whole will be amazing, but we don’t know the numbers yet.


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