About five years after the prototype was unveiled, yesterday Tesla took the wraps off its long-awaited Semi long-haul truck at an event at the company’s Sparks, NV, Gigafactory called Giga Nevada, which the company says produces the most battery cells in North America along with drive units and battery packs. The main event was a presentation from Elon Musk, Tesla CEO, and Dan Priestley, Senior Manager, Semi Truck Engineering, and the first official customer handover to PepsiCo’s Frito-Lay, which completed the truck’s first cargo run from Modesto factory to the Sparks event with a load of snacks.

Tesla pitches the powerful, efficient, fully electric Semi as the future of trucking, and the performance numbers are impressive. According to the company’s website, a fully loaded Semi at 82,000-lb gross combination weight has a range of about 300 or 500 mi depending on battery capacity thanks to its less than 2-kW·h/mi energy consumption. (Though battery capacities weren’t given, that would equate to a range of about 600 to 1000 kW·h or less.)

Three independent motors on the rear axles can accelerate the Semi from 0-60 mph in 20 s, fully loaded, and maintain the highway speed limit up a 5% grade.

 

Why long-haul trucks?

Tesla is tackling the truck market in its mission of making energy and all transportation more sustainable. While the sales volume of heavy trucks is small compared to that of passenger vehicles, their environmental impact is much greater. By Tesla’s estimates, trucks are 1% of vehicle production but they represent 20% of vehicle emissions and over a third of particulate emissions. From a health standpoint, particularly in cities, replacing diesel trucks will greatly impact human health, according to the company.

“So that’s why we’re doing it,” said Musk. “In addition to climate change and global warming matters, [electric trucks are] also quiet, going to improve the quality of air and improve the health of people living near freeways, which is obviously a super big deal.”

Tesla is also looking to reduce the cost of cargo transport and make it fun, said Musk: “We want to make the truck an awesome driving experience.” The company also intends to make trucks more appealing from a design perspective.

“That thing looks like it came from the future,” said Musk. “There’s actually a big shortage of drivers. So, if you’re a truck driver and you want the most badass rig on the road, this is it.”

According to Tesla, the benefits extend to the customers’ bottom line too. It says that charging with electricity is about 2.5 times cheaper per mile than refueling with diesel, based on average diesel prices in California between February-July 2022 and typical electric rates.

Operators can see estimated fuel savings of up to $200,000 within their first three years of ownership. With remote diagnostics, over-the-air software updates, and fewer moving parts to maintain, operators will spend less time at service centers and more time on the road.

 

Proven 500-mi range

While industry observers have been skeptical that Tesla’s claim of a 500-mi range was possible, Musk and company appear to have proven them wrong. They showed a sped-up video of a California test run completed on Nov 25th from Freemont to San Diego with a 4136-ft elevation pass around Grapevine in between.

“Some people out there say ‘can’t be done,’ and so we just did it,” said Musk, who promised that the whole unedited video would be posted on YouTube with no jump cuts.

Priestley added that it wasn’t done “with some ultra-clean, precise test track simulation or something where we shut down a road.” He emphasized it was the real world, over Grapevine, with traffic, loaded at just under 82,000 lb, with no special aero treatments, on a truck that came off the line—for a true 500-mi run on a single charge.

The team used a rolling-road wind tunnel and pulled in a lot of the learnings and features from the car side, but the truck and its trailer must work together, said Priestley. So, engineers spent a lot of time testing with both tractors and trailers, virtually as well as in the wind tunnel.

The Semi is “really efficient in every way,” according to Musk. “Aerodynamic efficiency obviously matters a lot. You can see it’s shaped like a bullet,” comparing the Tesla to an outline of a typical big rig “barn wall” during the presentation.

To create its class-leading Semi, Tesla engineers also leveraged the company’s experience and competitive advantage with existing drive units, power electronics, infotainment, efficient heat pump HVAC systems, and state-of-the-art inverters.

In general, company execs and industry observers also believe Tesla products benefit from the company’s full vertical integration on both the software and hardware side.

 

1000-V powertrain

Impressive acceleration and towing performance were musts for the Semi.

“At Tesla, we don’t make slow cars,” boasted Musk. That had to translate to the Semi “beast,” which “has crazy power relative to a diesel truck. It’s fast to accelerate. It’s fast to brake. It’s really a step change improvement in what it’s like to drive a semi-truck.”

Power figures were not given during the presentation, but Priestley added that “we’ve got three times the power than any diesel truck on the road right now. It’s a beast because it’s also efficient.”

It’s the mix of those two factors—power and range—that makes the Semi a game changer, said Priestley.

The performance is enabled by Tesla’s new 1000-V powertrain. While debuting on the Semi, Priestley says that more of the company’s vehicles will be getting it—which is a significant step up from the company’s 350-450 V range and leapfrogs the 800-900 V passenger car competition.

The Semi uses the tri-motor powertrain with “carbon-wrapped sleeve” motors from the Plaid Model S and Model X passenger vehicles. One of the drive units is constantly engaged, while the other two disconnect to improve efficiency.

On a highway, the single unit is doing the bulk of the work and the system is operating at peak efficiency. The other two units connect for torque and acceleration.

“The cool thing is that these are clutched automatically,” said Priestley. “If the driver puts their foot to the floor, the torque units spin up, clutches engage, and take over—and it does all of that before we’ve maxed out the torque on the efficiency unit. It’s completely smooth. There’s no turbo lag or jerkiness [and] no driver input needed.”

Even at a maximum weight of 82,000 lb, with the 2000 lb extra that’s allowed by law for electric trucks, the Semi can cruise on a small motor that can “fit in your luggage” but is more powerful than a diesel engine. However, when a mountain road like Donner Pass shown in the video presents itself, the Semi at maximum weight, can call on its other motors to power through a 6% grade and still accelerate. On the downward slope, the Semi can recapture much of the elevation’s potential energy with regenerative braking.

“Rather than using a Jake brake or engine braking like a diesel truck does, where you have to worry about hitting your shifts, if you miss a gear, you’re on your brakes and potentially in a runway situation, you don’t have to worry about any of that,” said Priestley. “On top of it, it also is a safer system for not just the driver, but everybody on the road because there’s no gear to miss.”

Also unlike diesel trucks, brake overheating is not an issue, so runaway truck ramps aren’t needed.

“We get to the bottom of the hill, we have cold brakes,” said Musk. “That’s mind-blowing in the trucking world.”

The Semi comes standard with active safety features—though no mention of specific automated driving systems was given—that pair with advanced motor and brake controls to deliver traction and stability in all conditions. However, the traction control benefits from the precision of the Semi’s electric motors, automatically stopping the truck from jackknifing.

“It’s doing all the safety stuff in the background that just isn’t possible with regular diesel trucks,” said Musk. “It’s a step change in technology in so many ways.”

 

Megacharging, and for Cybertruck too

To quickly charge a high-capacity EV like the Semi, high-powered chargers are a necessity. So, Tesla has developed a megawatt-class DC charger it calls a Megacharger. In combination with the high-voltage vehicle network, it allows the truck to recover up to 70% of its range in 30 min.

It has next-generation immersive liquid cooling, so it doesn’t need “a gigantic elephant trunk of a cable,” said Musk. The conductor is immersed in water-based coolant, with isolation monitoring on the back end to ensure that it’s safe and delivers a lot of current in a small cross-section.

It has three times the current density of the company’s existing V3 Supercharger unit but in a similarly maneuverable cable. It will also be used for the Cybertruck and is coming to Tesla’s Superchargers next year.

Beyond charging, Musk says that the future of transport requires a sustainable energy infrastructure that includes power generation, storage, and transfer to vehicles. He said sustainable power generation includes solar, wind, nuclear (“which we should support,” Musk quipped), and geothermal. Since wind and solar are intermittent, a large battery pack can store the energy and buffer the power so that grids are not overloaded with spikes.

“Our Semi customers are actively deploying this today,” said Priestley. “We’re working with them so that they have the pathway to get towards a hundred percent sustainable future.”

Tesla can offer the full ecosystem to customers, with solar panel and roof generation, Megapack “massive” energy storage, and Supercharger and soon Megacharger transfer to vehicles. The Megapack offers not only peak shaving, energy modulation, and redundancy/backup.

“If we’re going to ask a fleet to take on these trucks and run them, they need to ensure that they’re going to be able to charge them and keep their fleet running in the event of a power outage,” said Priestley. “And that’s one of the things that we can do with the Megapack on site as well.”

 

‘Easy to drive as a Model 3’

Vehicle efficiency extends to the vehicle’s ease of use.

“We’re trying to extend the idea of this efficiency from not just while you’re on the road but into the yard as well,” said Priestley. “That means that drivers at the end of the day are spending less time at the yard and they’re getting home earlier. It makes their lives easier.”

The design team really spent their time researching and doing ride-alongs to understand how a driver works throughout the day.

“It’s as easy to drive as a Model 3. With basically no training, you can drive this—but you have to think bigger,” laughed Musk.

Inside, a central seating position gives the driver better visibility, while the all-electric architecture reduces both rollover risk and cabin intrusion in case of an accident.

The truck has a low floor, so the driver can stand in the cabin even though it has a day vs. sleeper cab. The amount of space is class-leading, including plenty of cargo space, due to innovative packaging.

A focus on brought-in electronic devices means there are a lot of plugs and wireless charging.

A one-touch suspension dump means it’s very easy to attach to the trailer, saving time and money, making fleets more efficient, and getting drivers home sooner, said Musk.