{{ At an efficiency of 1.64 kWh per mile, the Tesla Semi costs roughly 15 cents per mile to power. By comparison, a standard Class 8 diesel truck averages about 6.5 miles per gallon. Even using the relatively low Gulf Coast regional average diesel price of roughly $3.11 per gallon, a traditional semi costs nearly 48 cents per mile to fuel. }}
intercst
Weird, still testing?
This went in production in 2022:
“Tesla 500 mile range Semi Truck starts shipping this year, Cybertruck next year”
[1:25 AM · Aug 10, 2022]
With those amazing specs, one would think you’d see these semis all the time.
What was the cargo and weight?
I know that Pepsi/Frito-Lay has been using Tesla Semis for a few years hauling Potato chips.
I suspect the Mone Transport trial involved a mix of more common industrial freight items.
intercst
Exactly.
Potato chips don’t weigh much.
And that article is from 2022.
I don’t believe semi is much of a product as of yet, which is also true of a great many of “Tesla-adjacent” ideas.
I recognize they have had some success in EVs and battery storage and driver-assist, but, like with healthcare, a skeptical mindset is warranted with claims about Tesla “products.”
The gap between claim and reality can be large, maybe infinite in some cases.
They have semis hauling around roadsters on Mars already.
Others have pointed out the gap between Tesla’s statements and a real product, offered in mass-produced quantities. But turning to your original point - is that savings good enough? A quick Google search shows that the Semi costs about $290K for the LR version, compared to about $170K for that standard Class 8 diesel tractor. So even if you were saving $0.33 per mile, it’s going to be more than 360,000 miles before you “break even” on the higher capital costs - six or seven years down the road, since you don’t get those electricity rates unless you’re using this as a local or regional fleet vehicle, not long-haul. And that’s ignoring cost of capital/time value of money - you might never break even on that exchange, depending on how quickly you rack up miles.
The numbers almost certainly don’t work for long-haul trucking. Because if you’re long-haul trucking, you’re going to have to pay third-party charging rates - likely to Tesla. So you’re not paying the $0.09 per kWh that industrial users get, which that low cost per mile is based on. You only get that if you’re charging at your own facility - you’ll pay much, much more if you’re charging on the road. Tesla charges between $0.25-0.40 per kWh for supercharging. Even at the bottom end of that scale, your charging costs would jump up to closer to 45 cents per mile. Saving literally nothing compared to diesel fuel.
Unless you happen to be lucky enough to have two facilities with their own infrastructure a convenient 300 miles apart. You might make use of one within a 150 mile range (less, actually, to leave some margin of safety) or 250 mile for the larger and more expensive version (and ditto for the MoS).
That said, there’s a reason why the military standardizes on just a couple calibers of ammunition, or why an airline doesn’t just buy any aircraft from any manufacturer - the standardization makes logistics infinitely easier. You don’t have to stock parts from 5 different aircraft; you don’t have to keep 20 kinds of ammo and figure out which type goes where. More to the point, there is a natural impediment to too much “mixing of fleets”; you need mechanics (or independents) capable of handling quite different systems: oil vs electrons, you have to create charging infrastructure, and you have to plan your operations around which vehicle can do which task.
None of this is to say there won’t be some sales of EV trucks going forward, just that it’s not likely to take over the industry the way the breathless promoters would like, at least not in any short time frame.
How come cars replaced horses so quickly? 
The Captain
Because cars offered completely different functionality than horses.
EV’s generally offer the same functionality as ICE cars. They differ in their fuel source, and there are modest differences in how they drive. But for the most part, they are fungible with ICEs in terms of how they operate and how they are used. In a way that horses and cars were not.
Follow the money.
The Captain
What does that mean?
Save them enough money and they will line up to buy.
The Captain
Technically speaking, they didn’t. In 1920 barely 20% of households had a car. That’s almost two decades after Henry Ford, and double that for Karl Benz. As late as 1950, only 50% of US households owned a car. Admittedly the Great Depression and the Second World War stunted adaptation (actually brought it down!), but still, 75 years from the invention, almost 50 from the mass production miracle, and still less than half of households (not people: entire households) didn’t have one.
But albaby’s point is made: this is not that. Trucks already exist. Their utilty is undeniable. This is about changing fuel sources, which is difficult but not moreso than stringing hundreds of thousands of miles of asphalt to accomodate them. I’m not saying EV trucks won’t be successful, just that there are factors working against instantaneous mass adoption.
That I can agree with, the supply won’t be instantaneous either.
The Captain
Right. But that was the point I was trying to make above. This doesn’t seem to save them very much money. Operating costs for fuel are much lower. But the difference in capital costs for the semi ($290K vs. $170K) is very high. That makes it unlikely that they’ll be able to save much money. Of course, that depends on things like cost of capital and how many miles you drive per year and whatnot. But a $120K delta on initial cost is hard to make up in those kinds of fuel savings.
Especially since you are only going to get that cheap electricity if you’re fueling at your “home base.” That means that you’re not using these vehicles for high-milage long-haul routes - which limits how many miles you’ll go through in a year.
Companies testing Tesla semi’s don’t seem to think like you do. Who should I trust?
The Captain
A careful reading of the articles. The companies testing Tesla Semi’s aren’t saying anything inconsistent with what I’m saying.
For example, the company in the article in the OP tested Tesla Semi and found that it had a fuel economy of 1.64 kWh per mile. You can trust that they’re not just making that up. But you then have to go a step further and figure out what that means. Because the company doing the testing didn’t do a price comparison.
If one does most of their recharging at an industrial facility, they should be able to get electricity at about $0.09 per kWh - which would yield that $0.15 per mile rate. But even then, that has to get balanced against the approximately $120,000 difference in price between the Tesla Semi ($290K) and the typical Class 8 diesel truck tractor ($170K). That’s a very large difference in price. So even at the fuel cost of $0.15 per mile, it will take more than 350,000 miles of total travel for that extra cost to get eaten up, which will take several years.
If they don’t do most of their recharging at their own industrial facility, they’re not going to get anywhere near that price. Commercial users pay more than industrial users, and third-party charges typically charge customers even more than commercial rates. Which makes sense - they have to cover their fixed costs as well as the cost of electricity. The lower range of Tesla supercharging prices are around $0.25 per kWh, and the cost per mile at that rate is about $0.41 per mile (compared to the $0.48 per mile for diesel). You’d never recoup your investment at that price, and the Semi would cost you vastly more than an ordinary diesel truck.
So trust the company to be reporting what they report, but look at what they’re actually saying and figure out what it actually means. Which in this case, is not that Semis are necessarily going to save you much money compared to a diesel alternative, absent certain specific instances where your mileage and cost of capital might make it worthwhile to consider.
It’s simple.
No one is buying semi in a serious way: so no market (or a small market at best).
I haven’t seen any mention of the cargo that was tested.
What weight was hauled?
That’s something important in logistics.
I think they probably do. Volvo, Freightliner, and Kenworth also make electric class 8 semis. Similar to Tesla, this has translated to lots of interest and not a lot of sales.
If the interest was there Tesla would have been building these years ago.
The Semi GigaFactory is just being completed in Nevada
https://electrek.co/2025/04/28/tesla-gives-update-semi-factory-on-track-volume-production-2026/
The Captain