This Might Just Be A Tesla Semi Mule – Video


This super-quick electric semi is more than likely a Tesla Semi test mule.

Yes, it could be any semi right?

Well, first of all, it’s almost surely electric. You can hear the brakes and other vehicles in the area, but when this “beast” accelerates, it’s not only ridiculously silent, but also crazy fast. Added to this, it has a strange, box-like, concealed area covered by a cloth, which is likely the battery pack. This would be especially true if it’s a test mule since there wouldn’t be a designated area to place and conceal the battery.

We recently showed you a picture of what many believe is the Tesla Semi prototype. According to Electrek, it was being tested in California in an area that some say Tesla uses for testing. Additionally, Musk did previously state that testing was taking place with a mule. Keep in mind that the mule and the prototype are two different vehicles. In the picture below, you can see what’s believed to be the prototype, on the trailer in the middle. You can see the extended portion on the prototype, which potentially houses the battery pack. However, take a close look at the red box:

Tesla Semi

A YouTuber posted this Imgur image link in the video comments. It shows a semi that looks nearly identical to the one in the video. You can see the same fabric-covered area (likely concealing the battery pack).

As people speculated about whether or not the photo was really the Tesla Semi, or something photoshopped, or something else entirely, CEO Elon Musk took to Twitter and provided a wishy-washy response.

While we have no way of knowing if the information is accurate or not, Electrek reported that an individual familiar with the program confirmed that the picture was truly the Silicon Valley automaker’s electric semi. If this is true, then the above video is almost surely the test mule.

Can you see any exhaust pipes in the video? How about the sound of a diesel engine or diesel emissions heading airborne? The person with the camera is very close to the truck, and the diesel engine note at that level of acceleration would be incredibly loud in the clip (not to mention that level of acceleration is not in a diesel-powered truck’s repertoire).

We should know more when the semi is officially unveiled on November 16, or at some point after that if the event is pushed back again.

Join us at InsideEVs new forum and let us know what you think.

Source: Electrek, Imgur

Categories: Tesla, Trucks

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41 Comments on "This Might Just Be A Tesla Semi Mule – Video"

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Your forum requires moderator approval to post… even after email confirmation. Seems like you limit/filter opinions…

Which would be great, considering all the “religious” nonsense that fill up most of the article comments.

John S, yes, the first post needs an approval, and we are keeping a close eye on it, so one shouldn’t have to wait long.

It’s just a spam-prevention tactic, apologies for any inconvenience. We are definitely not trying to limit opinions.

Considering the amount of bot generated junk and the unthinking vitriol on other sites, I think Insideevs has found the right balance of inclusion while still drawing the line on abusive posting. And taking a bit of time to have a person look at the first post is a really good idea. Keep up the good work Domenick! Insideevs is doing moderation right.

That is certainly an electric truck.

I’m more impressed with its smoothness than its quickness, since the box is probably empty. But there is no apparent clutch release with the usual shuddering that diesel trucks have, and no engine spin up.

It did produce a little growl when it departed, but perhaps that’s an artificial sound. But no smoke, no exhaust.

Yep, seems to be the case.

But at the beginning of the video, you clearly hear the truck’s engine start, so whatever this is it doesn’t seem “full electric” ?

I believe, it’s a car in the surrounding parking lot and if you listend the sound, it depart before the truck, shut down the hazard and pull away.

no exhaust pipes and quiet, must be EV or Hydrogen.

Early in the video you can hear an engine start. You can hear the engine quietly idling during the rest of the video. There does seem to be a sound of something that sounds like a quiet engine as the truck departs. I agree there isn’t the usual slowdown when shifting and there is no smoke. Doesn’t look conclusive to me either way. It does seem to match the truck in the photo with the prototype.

You’re absolutely right. I had to watch/listen to the video a second time, with the sound turned up (fortunately I have my computer sound routed into an excellent stereo system), so yeah, this is definitely a diesel semi.

And therefore, very unlikely to be a Tesla test mule, despite what the guy who uploaded that to YouTube thinks.

Could be a diesel generator with a small battery pack.

That way they can test electric motors and other systems without having to install a huge battery pack in the mule.

It sound more like a tuned gas engine than a knocking, clocking, vibrating diesel.

The driver also look disrupted by the onlooker filming.

“I agree there isn’t the usual slowdown when shifting and there is no smoke.”

Probably the rig is running empty, and the driver started out in a higher gear than what they use when pulling a heavy load, so no need to shift gears in the first few seconds after pulling out.

And any properly maintained rig shouldn’t be showing visible smoke, especially not with modern soot filters installed, and most especially when pulling an empty trailer.

All just my opinion, of course. I’ve ridden with a big-rig trucker, and I’ve driven a diesel farm truck, but I’ve never actually driven a big rig.

The sound could just as easily be from a speaker to hide its testbedness.

Very intriguing video and backed up most definately by the spy photo of the Tesla semi. If not an elaborate Photoshop scheme ( Why would anyone do that?! ) It’s pretty solid that the coincidence of the semi in the video show up next to the Tesla Semi on the trailer. Great sluething by an attentive bystander – or an elaborate ruse. I tend to believe it is a Tesla Semi mule. It brings up tantalizing questions. Does the Tesla semi include a diesel engine to pump up the airbag suspension and air brakes, or is it a range-extender? Pushmi is certainly right. I don’t have elaborate external speakers on this PC, just standard tiny HP ones – but I heard the diesel engine start up at the beginning the first time I played the video. That said, the truck scoots off without shifting nor smoke – and at a smooth, rapid rate. Very interesting indeed! Nebula 1701 could be right also. How better to disguise the test rig than to pipe diesel sound out of speakers? Fisker Karma had the goofy space sounds piped out of speakers in the front of the car – AND here’s a geeky blast… Read more »

I noticed the engine start sound as well, but there is no guarantee that isn’t another ICE vehicle somewhere close that we simply can’t see. I tend to think the evidence here is much more in favor of this being an EV or hybrid truck of some kind.

Fast Forward until 1:20. You’re welcome 😀

It’ll be nice to not have to change lanes every time you pull up behind a big rig at a light anymore!


The beige box behind the cab in the spy photo pretty clearly is larger than the one seen in the video.

The problem here is the rather large leap to a conclusion, from seeing another semi tractor in the same “spy photo” as the supposed Tesla semi tractor prototype, to the conclusion that the other tractor is part of Tesla’s BEV semi testing fleet just because it’s parked in the same area.

Now, as to the semi tractor seen in the video, which somebody is just guessing is Tesla’s: It certainly could be the same semi tractor seen in the spy photo, which may or may not be a Tesla “semi mule”. If it is the same, and if it really does belong to Tesla, then they tested it with at least two different covered add-ons which may or may not be battery packs. The covered add-on in the spy photo is pretty clearly larger than the one seen in the video. Of course, it’s entirely possible Tesla tested their semi mule(s) with different sizes of battery packs.

You have to zoom into the red square but after you do, you will see they’re both the same vehicle yet with different sized battery packs…


Yes this news has been out a while.

I think the size of the supposed battery packs in the mule is very interesting as well. The one in the video looks like it MIGHT be 4 stacked 100D packs….but it makes total sense for a proto type. You are testing the motors and so forth, stacking P100 packs makes total sense.

I think the real question is how much better could tesla pack the cells if they designed from scratch.

…much better I would think

A “Tesla Semi” sounds like something the fanboys get when Musk sends out a new tweet lol!

I have to admit that I have no clue how this is supposed to be a Tesla anything. You hear the thing start up at 8 seconds in and with headphones I can clearly hear a diesel engine with the clutch being dropped and RPM’s rise after. I’m pretty sure I can even see the bucking and speed change of at least 2 or 3 gear changes in the video.

Just had a thought. There are those that say this is a pure electric testbed and others say this isn’t one but just a diesel truck.

What if it’s both? They might have a clutch or something to separate the electric motor from the wheels when they aren’t testing the batteries or something goes wrong?

Could be the Cummins truck testing w/their diesel range extender.

A truck which accelerates “crazy fast?”. No thanks. Remind me to contact my congressman. Drugged out truck drivers are bad enough with their slow trucks.

Yep, self driving for the win!

I’m not sure. .
A new modern diesel truck does not smoke.
They could be fitted With a smooth semiautomatic transmission and the acceleration is not crazy fast. If the load is not heavy, and it has 600+ hp it will move.
Not the best exampel but

Or if you drop particle filters, add straight exhaust and 2000 hp:

But would be great if it was the Tesla. Why do they use air breaks on it? Electric brake calipers exist. Less complicated, less maintenence, easier to control electronically. Advanced regen..
Would not the Battery be lower to the ground? There is no driveshafts or diesel tanks in the way..
I say no to this.
More likely a cummins, or hybrid of some kind..

Air brakes may be required for this size of rig like side view mirrors.

I’m convinced it’s the Cummins test mule with the range extender option:

Shoot, I thought it could be a Daimler project being that the white trucks are Daimler Cascadia bodies…

Or it could be the Cummins project…

But why then is the exact same cab configuration with seeming battery pack in back seen just yards away from the Tesla Semi in the spy photos?

Thats conclusive evidence in my book that it’s a Tesla test mule of some sorts.

I also hear the starter motor and diesel fire up right at the start of the video – coordinated with the pumping of air brakes sound and flashing of side lights. Pretty much impossible for another vehicle in the background to be that perfectly coordinated with those visible and audible events.

This deepens the anticipation of the reveal. Is this all planned to get people talking before November 16? And do I buy the reasoning for all the pushbacks of that date?

Hmmm… And Musk said the Semi was a relatively easy undertaking…

*Daimler Freightliner Cascadia truck used as test bed.

Well the video with the mule seems to be taken at Pyramid Semiconductor Corp
1249 Reamwood Ave,
Sunnyvale, CA 94089

Which is only a few mins from the Tesla factory.

The engine start-up noise sounds like a car in the parking lot. The mule seems to be electric from what I can tell.

It’s not an electric semi, you people need better speakers. It clearly starts up, idles, and you can even hear the engine as it drives off. At 1 minute and 28 seconds the engine noise changes as the truck switches gears.

The truck at the test facility is the exact same truck. I’ve blown it up on screen and every last detail is the same. The battery pack is exactly the same as well down to every nook and detail. Remember, one is in the desert sun and the other is a video taken with buildings and trees around under different sky conditions. Just different lighting and a totally differnt angle and the opposite side showing in the photo. There is one difference I can see. That is the black cable rising from top to bottom near the right rear of the truck in the video which is not on the left side which is showing in the photo. Otherwise – use the split rear windows of the cab as reference and the length of the pack to the rear wheels. They are exactly the same – video to photo. I draw visual art. I know my angles, and the reason some think the battery pack in the photo truck is larger or a tan color is only perspective due to a completely different angle. Color of the battery cover is only the difference in natural lighting. If that is not… Read more »

If i was given the task to test a battery drivetrain on such vehicle in a cheap and fast way I wouldn’t bother spending time and money on removing the diesel-engine if it wasn’t absolute necessary. If I removed it I would have to reinstall Electric braking compressors, 24VDC power, Electric air contidion etc. etc. By keeping it I already have all auxiliaries working.

Then it is only to remove the driveshaft and replace with electric motor and reduction gear. If I am Lucky it will fit between engine and drive wheels. Then battery-packs and drive Electronics on the back. It doesn’t matter if we use some space here as long as the trailer can be hooked on.

I would need to keep the engine running during driving, and probably rev it up a little bit to make sure generator, compressors and pumps work as they should. Many doesn’t work well at idle speed.

Now this is no proof that the vehicle in the video is actually a bettery electric test vehicle, or that it is teslas, but the scenario fits pretty well.

It may have been that the standard Diesel engine was being used for the pressurized brakes etc. but I’m just speculating.

Maybe they built a real life Lego Technic drive system with a motor behind the white fender that is coupled to a gear on the factory drive shaft. It would allow the ICE to drive the truck if the electric system failed while testing and the location of the motor would fit with Tesla’s design goals (semi frunk).

Sound,could be an Air Compressor, that would need to start and build up before it moved.

Accelerating from a dead stop like that, it looked too linear to be a completely traditional drive train.