Tesla Semi, a deep dive
Well, looks like this deep dive went semi-viral.
This is one of deep dives I sent to my 2,300 newsletter readers. Get my EV industry newsletter every week by joining for free here.
"Even with big breakthroughs in battery technology,
electric vehicles will probably never be a practical solution for things like 18-wheelers, cargo ships, and passenger jets.
Electricity works when you need to cover short distances, but we need a different solution for heavy, long-haul vehicles."
— Bill Gates, 2020
"If Tesla really delivers on this promise, we’ll obviously buy 2 trucks —
one to take apart and one to test because if that happens, something has passed us by.
But for now, the same laws of physics apply in Germany and in California”
— Martin Daum (Daimler Trucks), 2018
"IF that happens, something has passed us by."
IF that happens...
IF that happens...
IF that happens...
IF that happens...
"There are some people out there that say it can't be done. I don't know who might say that, but I've heard rumors.
So we... just did it.
And we'll post the whole video, unedited, on YouTube."
— Elon Musk, 1st of December, 2022
On December 1st, Tesla delivered its first Semi trucks to PepsiCo and its subsidiary Frito Lay.
You can jump into relevant sections by clicking on any of these:
- Specifications
- Power
- Efficiency, 500-mile test
- Charging
- Other features
- The first client
- The info that we are missing... and me trying to fill the gaps:
* curb weight
* battery size
* charging capability - Competition
Or just keep reading to get the full scope.
Here's the full delivery event live stream (36 minutes):
Disclaimer: I don't know much about trucking.
But I will give you an overview of the event from an EV nerd point of view and sprinkle the other related stuff I've learned about the Semi in between.
Specifications:
- Range: over 500 miles when fully loaded, at total weight of 82,000 lbs / 37,195 kg
- Acceleration: 0-60 mph with a full load is around 20 seconds.
- Speed: Maintains highway-level speeds even up steep grades.
- Charging: 0-70% in 30 minutes
- Seating: The driver position is in the center, with two 15'' touchscreens facing the driver on each side, possible to stand up in the cabin.
- Efficiency: <2 kWh per mile officially, although Musk said separately it is currently 1.7kWh/mile, with a clear path to 1.6, possibly 1.5.
- Powertrain: 3 motors, 1000V architecture
- Price: initially $150k for the 300-mile version; $180k for the 500-mile version and $200k for Founders Series.
We have several questions that aren't yet officially answered, like the battery size, curb weight of the Semi without load or trailer, its charging capacity, etc. I will do some back-of-the-napkin calculations for each of these at the end of the article.
Before we go deeper, here's a brief reminder that I write an EV industry newsletter every single week to 2.3k+ people. You can join by just dropping your email here:
Power:
The tri-motor powertrain system, which is using the Plaid Model S&X powertrain, enables two of the power units to disconnect so they are not free-spinning at cruise, but are in reserve for torque and acceleration.
This improves efficiency significantly and at cruise, all work is done by the one 'highway drive unit' which carries all of the 82,000 lbs.
One of these motors should be the equivalent of a diesel engine, so 3 makes it 3x the power of a diesel truck. For size accuracy, Dan shows the size of the whole drive unit:
The Semi carries over the proven tech from Tesla's other models made at volume:
Efficiency, 500-mile test
A key point of the unveiling was the demonstration of a 500-mile fully loaded trip. They drove the payload from Fremont to San Diego without charging and just a 30m break in between.
The gross weight totaling 81,000 pounds (36,741kg).
Here's the timelapse (video):
And here's the graph of the whole trip. The blue line shows the battery %, while the grey shadow shows the elevation:
The route has a 4,146ft (1,264 m) peak in between. It's especially interesting to see the charging curve drop uphill and the re-gen replenishes a nice portion of it going down the peak.
So we can see the 500-mile test was done with no special conditions, no aero treatments, no closed roads, no tricks, and no charging. All real-world stuff.
There's this 6% grade at Donner Pass that one of their tests went up on too (speed at 6% grade is a standard truck measure) and they uploaded a video about Semi passing an ICE truck on the way up at. The speed was increasing during the pass, we saw it go 45mph. As it was hidden in Tesla Gallery and not shared anywhere, I uploaded it on Twitter and... it went semi-viral:
The 14-second video has now been watched 928,000 times and it has reached over 3 million people. I guess the fact that Elon Musk himself liked the tweet had something to do with it.
This is our third tweet that he has liked so far, so I think you will notice that I'm getting more Tesla-biased now. Right?
What I find crazy is how many people in the replies think all of this is a complete scam, the Semi has to go charging on top of the hill for 5 hours, and the batteries are clearly dead within a year. Some even think the payload weights were made of foam. C'mon...
Aerodynamics: Tesla says the Semi is designed like a bullet, not a barn door, I assume he is referencing the ICE truck outline:
Charging
To charge the Semi, Tesla developed a MegaWatt-class charger (V4), which has a liquid-cooled cable, as the high voltage conductors are immersed in coolant return tubes:
It seems during the speech, they are implying the MW (V4) won't differ too much in size from the V3 charger cables that you see in Superchargers today. The same system will be used for Cybertruck too. This is coming to the Superchargers next year.
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Other features:
Photos & videos were prohibited in most areas of the tour so we aren't seeing the production line yet. But we did get this little showcase from the official Tesla gallery (link):
Here's one of the videos I found from Arash Malek aka Minimal Duck with actually going inside the cabin and also filming other angles around the truck.
If your question ever was "can I drive over a ladder like it's nothing?" then the answer is yes, yes you can. Here's a video of some of the reliability & durability testing the Semi went through:
Tesla plans to be its own customer, using Semis to transport goods between plants and suppliers "to close that feedback loop" and refine the truck. "These Semi trucks are running 24/7 between Sparks... and Tahoe"
Some of the other features worth mentioning:
- The brakes don't overheat thanks to the re-gen use. After the Donner Pass, the team when stopping at the bottom of the hill, found the breaks were cold. No gear changes to miss either.
- Traction control is better thanks to the precision of the electric motor over the diesel engine.
- Musk claims it's as easy to drive as a big Model 3, and you could drive it basically with no training (but, you know, don't!).
- Features a one-touch suspension dump to attach to the trailer easily. The light Test, Air Brake Test also happen with a touch of a button.
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The first client:
Pepsico ordered 100 Tesla Semis early on after the unveiling in 2017, along with Anheuser-Busch, Sysco and others. In fact, here's a spreadsheet with 50 orders totaling 993 Semis which have been publicly announced up until the end of last year: (link).
PepsiCo plans to use the trucks at its Frito-Lay (its subsidiary) plant in Modesto, California, and its PepsiCo beverages facility in Sacramento.
The Modesto site is also the one receiving funding of $15.4M from CARB, which covers half of the $30.8M project to change its fleet to electric. (link) This includes 15 Tesla Semi trucks, six Peterbilt electric trucks, three BYD electric yard trucks, 12 electric forklifts and 38 low-emission Volvo tractors.
I found an interview from back in October 2019 where Michael O'Connell, VP of Supply Chain at PepsiCo said that at their Modesto facilities, their average distribution ranges at around 400 miles (video).
Semi's first cargo run for PepsiCo was delivering a load of Frito-Lay chips to the launch event. I know you're used to me using only high-quality images here, but I think this drone footage from the event site gives a nice feel (link):
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According to Tesla estimates, the Tesla Semi truck can save up to $200,000 in fuel savings over Diesel alone over a period of just 3 years.
The info that we are missing...
and me trying to fill the gaps
- Any autonomous driving/driver's assist capabilities.
- Exact price. We might assume that the last 5 years have increased the price from the initial $150k-$200k.
- Curb weight of the Semi without trailer and load. The big one, how much can it carry?
- The battery capacity.
- Peak charging capacity and the charging curve
Let's grab the last three and make some assumptions.
Curb weight assumption: 27,000 lbs
This seems to be the load used for the 500-mile trip that was tested, as we saw on the Donner Pass video. The picture is from a drone shot ( here ). Although, mind that there are no confirmations of the time-lapse 500-mi video load yet, I think we can safely assume that this is them loading the max capacity as there wouldn't be much point in testing less:
Let's go step by step, as detailed also here:
- The truck carries 11 concrete jersey barriers which weigh 4k lbs each.
This puts the total weight on the flatbed at 44,000 lbs. - A 53ft flatbed weighs about 10k lbs when empty. Total: 54,000 lbs
- We know the 500-mile trip was done at under 82k lbs, so at 81,000 lbs total weight it leaves 27,000k lbs to our Semi curb weight.
This would place the Semi about 5,200lbs more than the 220-mile Freightliner (Daimler) eCascadia (438kWh battery) and 2,800lbs less than the 330-mile Nikola Tre BEV (733kWh battery). See more in our comparison table below!
Battery assumption: 914 kWh
And range of 537.6mi fully loaded.
My back of the napkin calculations:
- We saw from the Tesla 500-mile run stats that it started at 97% and finished at 4%. So in reality, it used up 93% of the available capacity to achieve the run. This means 100% would give us 537.63 miles for a complete range. Note that we don't know the battery 'reserve' here so we'll assume and calculate the 'usable' capacity.
- Although general numbers say "<2kWh" efficiency per mile, Musk said separately they have currently achieved 1.7kWh and are on the road to ...1.5kWh. We'll go with 1.7kWh per mile here.
- With 1.7kWh per mile efficiency and 537.63 miles drivable range, the full usable capacity of the battery would be 913.97 ~~ 914 kWh.
Note that most media assumes the battery size is about 9% larger, at 1MWh. This might be almost the case if considering the reserve capacity (gross) of the battery. Creating the truck as efficient as possible will be key to unlocking an absolute winner of an electric semi-truck. And that's what Tesla Semi is.
Charging assumption: 1.28 MW average for the first 30 minutes
All we can go with is outline of "charges 70% in 30 minutes" here. At compatible Tesla V4 Megawatt chargers, most likely.
Two steps:
- 70% of the usable 914kWh is 639,8kWh, which needs to be 'filled' at 30 minutes.
- This would mean the charger would need to average at 2x that, at 1.28MW during the period. We can also assume that peak charging is higher as it varies throughout those 30 minutes.
70% in 30 minutes also seems like a wide approximate, where the likely results in ideal conditions are better than this.
I'm also very interested to see the charging curve to know at which point the charging drops off significantly towards the end.
Competition
The core competition for Tesla Semi are the diesel trucks on the road. That's what these electric Semis are meant to replace.
However, to objectively understand the innovations with the Semi, let's look into the other battery-electric Class 8 trucks that are in production now or just about to be. It took me quite some time to put this together:
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Long story short, Tesla Semi comes in massively ahead on any of the e-truck specs so far.
Tesla aims to produce 100 Semis this year (link), but considering the $40k credit kicks in January, we'll likely see them delivered early next year.
By 2025, Tesla wants to ramp up the Semi production to 50k/year.
I think it's fitting to end this deep dive with one of the delivered Semis 'out in the wild'.
Spotted by @bshaddix at the Modesto Christmas Parade:
