Tesla Semi reveal event

Tesla Semi reveal event

Or should we call them Tesla Semi “Wind wings.” Or how about “Gap Flaps”?

The Tesla Semi has very low drag. One way they keep drag low is to close the gap between the tractor and the trailer.

Figure 1

Figure 1

It appears that these aero panels move depending on the yaw angle of the trailer. It’s pretty clear if you watch the first 20 seconds of the YouTube Tesla Semi "Reveal" video:

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There’s no mistaking it if you look at this screenshot:

Figure 2

Figure 2

Also if you look at a shot of the tractor from the rear, sans trailer, you can see what appears to be actuators to move the panels:

Figure 3

Figure 3

How much the “movable” part actually helps the aero characteristics is probably debatable. However, it seems obvious to us that they move out of the way to keep the tractor from hitting the side of the trailer when the trailer is cocked at a big angle.

Whatever the reason: pretty darn cool in our opinion.

You can also see the "flaps" in the recent video of the Tesla Semi driving on the highway:

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Thanks to my research partner Keith Ritter for spotting this!