Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Tesla Semi

This site may earn commission on affiliate links.
I'm not having the easiest time finding all of the data online, but I did find that one particular engine (Detroit Diesel DD15) for a long range semi is about 2,880 lbs. A transmission (Fuller 8LL) weighs 690 lbs. There is, of course, the lack of fuel in an electric semi, and some of the other drive components (shaft, differential) which won't exist. But that's only 3570 lbs. My X weighs over 5200 lbs.

I'm probably missing something.

So we lose:
  • Engine: 2,880 lbs.
  • Transmission: 690 lbs.
  • Fuel: 125-300 Gallons, so let's say 213 @ 6.073 lb = 1,294 lbs.
So we lose at least 4,864 lbs.

But you gain:
  • 3) 100kWh packs @ 1,500 lbs/each = 4,500 (2170 based packs should weigh a little less.)
  • Electric motors: ~500 lbs each. (including invertor and differential) probably need 2? 1,000 lbs.
So you gain 5,550 lbs.

For a net difference of 636 lbs. (And I am sure there could be more weight savings, but you might need another battery pack...) Of course there are other things like cooling systems, etc. So with some work it should be reasonable.
 
Last edited:
I'd surmised battery-swapping over in the "You Called It" prediction thread; feel free to surmise all you care to here but don't hold back posting your specific Best Chance Ideas over there as well.

I've been a table-pounding proponent for battery swapping since before Tesla was a twinkle in Tarpenning/Eberhardt/Straubel's eyes - very old history - so I definitely have an axe to grind here but I absolutely believe it is a match made in heaven for long-distance, hub-centered freight hauling.

Now, as far as GoTslaGo's observation:
Find it interesting that the most common job in DC is a "Lawyer" since 2000. Previous to that it was "Secretary". Except 1994 where is was "Lawyer", then followed by 1996, where it was "Janitor". What's up with 1996?
Well, every generation or so someone has to clean up all that mess
 
1. Battery swaps are not a great idea for semis, or whatever we call the future of over-the-road cargo transport vehicles. Trying to apply battery swaps to e-trucks is an attempt to solve tomorrow's non-problems with a solution of today. Most likely is that the concept of battery swaps will be quickly OBE by development in charging infrastructure, battery technology, and automation, and fundamental changes to trucking operations (like how an operator spends their hours). I'd guess within a decade. Almost certainly by gen2 trucks.

To make an analogy, in 2008, you could sort of drive your Roadster from SF to LA. In 2017 [with a 100D] you can practically make it without stopping, and can easily make the trip within minutes of an ICE.

2. A bit of a distraction here, but the solar option on trucks is the same as with cars, except the weight is more of a penalty and the annual offset is smaller (because of the annual mileage vs annual harvested ratio). Not much new here.
 
  • Like
  • Disagree
Reactions: Ibrido and T3SLA3
I'd surmised battery-swapping over in the "You Called It" prediction thread; feel free to surmise all you care to here but don't hold back posting your specific Best Chance Ideas over there as well.

That is the most logical thought and one that first struck me as well. But then I recalled that Elon said that 350kw charging was child's play and that made me think of what if... What if the Semi had 4 125kwh packs and each was completely self contained. This would facilitate pack swaps, but the normal operation would be fast charging all four packs at the same time with 700kw Supercharger v3.0. From 0 to 100% in 20 minutes or less?

A battery swap would require very specific infrastructure where as the Supercharger v3.0 upgrades could support all the vehicles. The only thing that would need to be accommodated would be more room for the rig to pull in. These stations could be out on the open road with huge battery and solar installs to support the entire thing.
 
One question that has me perplexed. Could Tesla also develop a hybrid trailer that could work with the new Tesla semi or really any semi. The trailers would have batteries, motors and could even be autonomous so that they could position themselves within a stock yard.

These trailers could be developed much cheaper and be put into work with existing trucks. Essentially he trailer helps push the semi and helps slow it with regen. They could be combined with the new Tesla semi for long haul, while the default would be setup for short haul.

Thoughts?
 
One question that has me perplexed. Could Tesla also develop a hybrid trailer that could work with the new Tesla semi or really any semi. The trailers would have batteries, motors and could even be autonomous so that they could position themselves within a stock yard.

These trailers could be developed much cheaper and be put into work with existing trucks. Essentially he trailer helps push the semi and helps slow it with regen. They could be combined with the new Tesla semi for long haul, while the default would be setup for short haul.

Thoughts?
I don't think Tesla will every develop anything hybrid. First it's against their goals and ideals, second they don't have the capability.
 
I don't think Tesla will every develop anything hybrid. First it's against their goals and ideals, second they don't have the capability.

I never said they would call it a hybrid or develop a fuel based solution in conjunction with battery power. I agree completely that they would never develop a hybrid solution of any kind. The batteries and EV power train is either ready to support the solution or they wait to do it. ie.. Electric Airplanes. I was just thinking a trailer that was a smart system unto itself that could be combined with existing trucks would hasten the transition. Initially I had thought about the advantages to the Tesla Semi. One thing to keep in mind is that the day that the Tesla Semi hits the roads there will be 6 million rigs on the road in the US alone. Only a few hundred thousand sold a year. Elon wants to save the planet fast, not in several decades. The format of the trailer would be awesome for battery packs and electric motors and the control you would get would enhance safety as well.
 
I'm not having the easiest time finding all of the data online, but I did find that one particular engine (Detroit Diesel DD15) for a long range semi is about 2,880 lbs. A transmission (Fuller 8LL) weighs 690 lbs. There is, of course, the lack of fuel in an electric semi, and some of the other drive components (shaft, differential) which won't exist. But that's only 3570 lbs. My X weighs over 5200 lbs.

I'm probably missing something.
I don't think we're far off. Consider that the 210kWh Powerpack weighs 3575 pounds, but it is nowhere optimized for transportation at a pack density of 129 Wh/kg or 59 Wh/lb. So I suspect that Tesla may be in a position to nearly double that. So let's say 100 Wh/lb is doable. That provides 300kWh for 3000 lbs, which leaves an extra 600 lbs. for the rest of the drivetrain.

Moreover, I figure that mile efficiency will come in at 1.2 to 1.5 kWh/mile. So 300kWh gets us to a range of 200 to 250 miles. So for roughly no weight incremental to DD15 engine, we've got a workable range. Suppose this is swappable in say 150kWh units and the tractor can hold upto 6 units. Then the rig can be fitted from 200 to 600 miles of range depending on the demands of next leg of the journey. I think the configurability of swappable units is very helpful. Some circumstances may actually call for 600 miles of range, but that would be venturing out where swap stations or charging infrastructure are quite insufficient. But the swapping network could be fairly dense for the most heavily traveled routes, so that swapping can happen every 200 miles. Most miles will not be overburdened buy surplus batteries, but the flexibility will be there when needed.

Also keep in mind that class 8 starts with gross weight of 33,001 lbs and goes up to 80,000 lbs. So taking on an extra 1500lbs battery occasionally is not that big of a deal. Sure, it can cut into the maximum load the rig can haul. But if there are genuine savings to be had in operating cost, then there is tolerance for lightening the loads or swapping more frequently.

One finally point is that it will take at least a decade for electric trucks to replace even half of the tractors in service. The limited supply of electrics will be deployed where it is most economical to do so. If diesels find they have niche in hauls requiring more than 400 miles range without crossing a swap station, then good for them. But in another ten years we could see pack level energy density rise from 100 Wh/lb to 200 Wh/lb. All along that trajectory, the niche for long-haul diesel keeps shrinking.

In twenty years time, Ice Road Truckers could make a comeback as the last frontier where diesels are still in use. Of course, electric drones will be flying overhead to deliver fuel to the trucks or pull them out of a ditch, but it will make for an interesting show. I'll get the question, "Grandpa, why don't they just deliver the potato chips by the drone?" And I'll say something like, "Oh, look! I think the ICE is going to crack. I love this part."
 
I too cannot see Tesla making a Hybrid truck. There are others doing so already. Check out Ian Wright's way of tacking the worst diesel polluters. .

I should not have used the word hybrid. Yes, and Nikolamotors.com is making a turbine hybrid as well.

My thought was less about a hybrid vehicle and more of a solution that could have A duel purpose and accelerate the transition away from fossil fuels. If not Tesla, maybe someone else will build them. I think its an interesting idea, maybe its really a dumb idea. I can just picture in my head autonomous trailers scurrying around the docks picking up shipping containers and delivering them to all kinds of rigs. Then I could see them actually helping a rig stop in an emergency and safe breaks during normal operations. The weight of the batteries being so low would also make the loads they carry more safe by helping keep them balanced. If the batteries do not take up the entire space, they could actually shift based on the load to help keep it balanced.

I wonder how much fuel could be saved if put two S100 under each axle of the trailer. Since the breaks are plugged in, it could sense when to apply regen breaking, acceleration could be a bit trickier.
 
I wonder about the shape of the cab.
Semis now seem comically tall and huge overall.

The current diesel dually pickups are near 1000ft/lbs torque and their engine bays are about 1/3rd the size of a semi.

An electric semi could have more of an El Camino type shape, or could retain the current semi shape and have a massive frunk....perhaps storage that was accessible to a forklift. If that were the case, small loads could be hauled without a trailer, which is another potential up side/business opportunity.
 
I never said they would call it a hybrid or develop a fuel based solution in conjunction with battery power. I agree completely that they would never develop a hybrid solution of any kind. The batteries and EV power train is either ready to support the solution or they wait to do it. ie.. Electric Airplanes. I was just thinking a trailer that was a smart system unto itself that could be combined with existing trucks would hasten the transition. Initially I had thought about the advantages to the Tesla Semi. One thing to keep in mind is that the day that the Tesla Semi hits the roads there will be 6 million rigs on the road in the US alone. Only a few hundred thousand sold a year. Elon wants to save the planet fast, not in several decades. The format of the trailer would be awesome for battery packs and electric motors and the control you would get would enhance safety as well.
I'm still not quite sure about your idea here. Do you mean the trailer would have energy and power, but still hatched to the rig (not familiar with semi terms, rig is the head part right?)? The purpose of the diesel engine powered rig would only be navigation? If so, and given it is the trailer taking up most of the energy consumed, why not make the rig electric as well?
 
I'm still not quite sure about your idea here. Do you mean the trailer would have energy and power, but still hatched to the rig (not familiar with semi terms, rig is the head part right?)? The purpose of the diesel engine powered rig would only be navigation? If so, and given it is the trailer taking up most of the energy consumed, why not make the rig electric as well?

Precisely, the trailer would be a complete system capable of some short range transport, typically around loading docs, shipping yards and so on. The reason would be that there are 6 million semis or tractors already in service and as we know, Tesla hasnt made 6 million of anything that large yet. The trailer is basically a flat bed with axles, wheels and brakes. The tractor plugs into the trailer for braking and break lights and other stuff, most of which I have no clue. The weight is all carried in the trailer, so having the trailer actually be able to assist the tractor in the process of the transportation would dramatically lower fuel consumption and allow you to leverage the current infrastructure how you build enough fully electric tractors. If would also allow fully EV tractors to be right sized so that when they transport larger loads, they can use trailers that has its own motors and batteries and smaller trailers/loads could be dumb trailers with no batteries and motors, though breaks could still be regenerative.

The problem you will have with long haul trucking is that you might need 1000+ kwh of batteries to drive long hours without stopping. But that would only be useful if you only ever had very heavy loads and needed to move them only over long distances. There is a lot of that going on today, but there is also a lot that is not long haul. So you build a tractor that is more generic and able to do many things, but is range limited to say 500kwh/250 miles. When you have longer range loads, that is when you use a trailer with motors and batteries. Same rig that is doing short runs, but now it can go farther. The same trailer could be used by diesel big rigs to dramatically lower fuel requirements, pollution, all while improving safety.
 
  • Like
Reactions: Fallenone
Agreed. And I would add on top the market currently dominated by FedEx and UPS. Why stop at manufacturing the trucks when you can also provide customers with a fully autonomous low-cost cargo transportation service? FedEx and UPS occupy just as much of the profit chain as Daimler.

One reason is the scale of the capital needed to build a replacement system. Using FedEx and UPS as examples, does Tesla want to design an integrated system that FedEx and UPS buy from them to implement, manage, and profit from (Tesla profits on the sale of the trucks, packs, and similar stuff). Or does Tesla want to try and take on building their own logistics competitor to FedEx and UPS, admittedly potentially lower cost due to lower fuel and maintenance cost, which will include taking on the financing / capitalization of that effort?

My immediate reaction as a TSLA shareholder - I want to see Tesla providing a highly usable system of vehicles and charging infrastructure (whether it's supercharging or pack swapping - I suspect in practice both are part of the solution) that logistics companies buy, and use to lower their cost of doing business. Let the Logistics companies take on the competition and optimization of the logistics business, and leave Tesla out of it.

An idea I got from reading Buffett a long time ago - some technological advances are such that all of the benefit flows all the way through to the consumer, and none of the benefit sticks to the implementer. Improving the cost of moving stuff around looks to me like one of those situations - competition between FedEx / UPS, and other movers of stuff is so big, I'd rather they herein a position where they had no choice but to buy the trucks, packs, and system from Tesla to stay competitive with each other. They bring the capital to the table that funds rebuilding the logistics infrastructure, and Tesla brings the products they all have to have to lower their costs.

Tesla stays focused on scaling up the building of the trucks, packs, etc.., and FedEx / UPS stay focused on optimizing routes and movement of stuff.


Of course I can be wrong, and I'll wait to change my current view when I have actual business model intent and information from Tesla. But my immediate reaction is that if Tesla is focusing on transport as a service instead of building a truck and charging infrastructure that every transport company HAS to have (and therefore buy), then that sounds like a company that's losing it's way on the stated mission / vision. If the vision is accelerating the advent of sustainable transport, then Tesla needs to act in a fashion that brings as many companies to the table as possible.

If the mission / vision is to take as much of the market as possible, and they apply it to a market this big, that's going to bring competitors out like flies, turn customers into companies that are looking for any and every alternative they can find.


Back to your comment - FedEx and UPS do take a big chunk of the value chain. If Tesla starts thinking they can take a significant hunk of the FedEx / UPS contribution to the value chain, that's sort of the same thing as Tesla going into competition with FedEx / UPS. (I'm using them as examples and stand ins for the larger idea). I don't see how Tesla has a paradigm changing way to provide logistics, nor how they keep it going.

I do see how Tesla can provide paradigm shifting cost shifting products to companies that do logistics and transport though. Do this, and Tesla will profit hugely, the acceleration of sustainable transport will continue, and we all win.

Try to compete with FedEx / UPS at what they do, and that sounds like business hubris on Tesla's part, and I'll most likely be back in cash :)
 
I never said they would call it a hybrid or develop a fuel based solution in conjunction with battery power. I agree completely that they would never develop a hybrid solution of any kind. The batteries and EV power train is either ready to support the solution or they wait to do it. ie.. Electric Airplanes. I was just thinking a trailer that was a smart system unto itself that could be combined with existing trucks would hasten the transition. Initially I had thought about the advantages to the Tesla Semi. One thing to keep in mind is that the day that the Tesla Semi hits the roads there will be 6 million rigs on the road in the US alone. Only a few hundred thousand sold a year. Elon wants to save the planet fast, not in several decades. The format of the trailer would be awesome for battery packs and electric motors and the control you would get would enhance safety as well.

I had this idea too a few years ago. Autonomy makes electric trailers even better, so the tractor is only needed last minute to take them onto public roads. So there are logistical advantages to exploit. Imagine trailers that move themselves from one bay to another so as to get loaded up. Less need to sort the load out within the warehouse before loading the trailer.

You make a compelling argument here that even before there are enough electric tractors to pull them, they can work with diesel trucks and displace fuel consumption all the same.

The general rule of thumb that I work with is that 8 kWh displaces 1 gallon of fuel in an ICE. So if a trailer had just 80kWh in its own pack it could save 10 gallons on a trip, maybe more with regenerative braking. So about $5 of electricity could save $25 of fuel @ $2.5/gal. Thus, the battery is creating value about 25c/kWh per cycle. If Tesla could prices this at $500/kWh or $40k for the battery and drive system, it would need a cycle life in excess of 2000 cycles which could be realized within 8 years of typical use. So this is an opportunity to sell something roughly on order of a car, but it would be cycled much more frequently than a typical private car. That cycle frequency is way enables a bigger fuel offset in a shorter time and makes higher cycle life valuable.

In addition to fuel savings and automated logistics, the electric trailer could reduce wear on the tractor.

Is this the best opportunity for Tesla right now? I doubt it. Getting an electric tractor on the market and developing infrastructure around it is much more critical than designing an electric trailer. But in a few years, autonomous electric trailers could become a logical extension. No point in getting the cart before the ox, but once you have an electric ox...
 
  • Like
Reactions: Intl Professor

Semi's mean five things:

1. Tesla-Elon have figured out a way that is cost effective to power huge trucks with batteries-electricity. That's huge! Since the MS was launched with an 85kwh battery pack no one else has caught up. How long before someone catches up with their semi? Moat!

2. It's a huge market. @DaveT has some excellent analysis that he or someone should post a link. Tesla is going to disrupt that market. This isn't the quote that I was looking for but it's helpful. But I disagree with his statement about manufacturing. I believe that Tesla's manufacturing is going to be a key reason for their ability to disrupt multiple sectors of our lives. I'm not sure that we have a current disagreement though, since I believe he wrote that before Elon's Production Epiphany aka alien dreadnaught production.
DaveT said:
Before going on, I have to say that I think the two big prizes in transport that are in possible reach for Tesla are ride-sharing and trucking. I don't think manufacturing is that sexy... it's too low margins and too high liability. If Tesla is going to succeed in a big way, they need to win in ride-sharing and/or trucking. The other big prize is energy. All three of these markets are trillion+ dollar markets, namely ride-sharing, trucking, energy.
Trucking and energy are both dependent on battery costs.
3. They are not dependent upon autonomy to reduce the costs. Because even if they had full autonomy ready today they could not count in regulatory approval. That's a good thing, it means that their solution will get even more compelling over time.

4. It should be easier for them to dominate produce enough vehicles to this market (smaller number of huge trucks), than cars, because mainly they need to scale battery production.Now that they have completed the first two cell production tranche's they will be able to complete succeeding Gigafactories much faster and for less money.
5. I think partly it's an extremely shrewd business move, but it's also a strategic move to improve the environment.

When the market figures out numbers 1 and 2 above the SP should rise.

Repeating myself this is huge!
 
Last edited: