About a week ago, Elon Musk hosted an event where he delivered the first of his Tesla semis to Pepsi. About four years earlier, he hosted an event where he introduced the semi along with a lot of inflated claims such as that convoys of them (each with their 18 squishy tires) are going to beat rail. He started taking deposits with a promise of delivery in two years. There’s tons of YouTube video channels (both pro and con) covering the semi. On the pro side, one that I watch quite a bit is Now You Know hosted by a couple of hard core Tesla fanboys named Jesse and Zac. It’s very well produced and has 324 thousand subscribers. They have extensive coverage of all happenings in the world of electric vehicles and they do lots of interviews with green energy type entrepreneurs. They usually start their show with personal endorsements of granola cruncher type product sponsors. They have lots of audience participation features such as pictures and videos of customized Teslas and new charging stations. They are almost cult like in their adoration of Elon Musk and even regularly parse his latest tweets. They’ve put down their deposit and are on the list to get a Tesla semi. They are understandably stoked.

On the con side, my favorite Tesla critic is Thunderf00t (aka Phil Mason). He’s a chemist who started doing YouTube videos probably about two decades ago to debunk creationists. He’s become very prolific making tons of videos on various science and technology topics acquiring a million subscribers along the way. He’s very good at debunking various energy schemes and scams in which he titles his videos “<scheme or scam> Busted”. He gained some note in the atheist/skeptic movement by siding with Richard Dawkins in a scuffle with a blogger named Rebecca Watson (aka SkepChick) which has likely caused the permanent rift in the skeptic community. Mason describes it well in an interview with Dave Rubin.

Mason is at the other end of the extreme from Jesse and Zac with an obsessive hatred for anything to do with Elon Musk. The vast majority of his more recent videos are about Musk. In this video he makes a calculation starting at about six and a half minutes in where he concludes that the Tesla semi will only be able to haul about five tons of cargo while a regular diesel semi will haul twenty. He does this by comparing the energy densities of lithium ion batteries and diesel fuel. I found this to be quite a revelation so I took a screen shot from the video and have been doing a lot of tweeting and commenting about it. I even noted it in my last post.

Well, I’ve been eagerly awaiting Thunderf00t’s new video on Tesla’s delivery of its first semi to Pepsi. Thunderf00t made a couple of early tweets:

He’s finally released his “Busted” video:

At about nine minutes in, he makes a load calculation from a widely circulated video of a Tesla semi passing another semi going up a 6% grade with a load of concrete barriers. He finds a web page with some similar barriers, gets the weight specification, counts everything up and calculates that the Tesla semi is carrying about five to six tons. There’s only one problem. Thunderf00t has looked up the wrong barrier and got the wrong result! And he didn’t just get it a little wrong. He picked a barrier that weighed half a ton, while a bunch of commenters and twitterers found the correct barriers which weigh in at two tons each. The load adds up to about twenty tons just like a conventional diesel semi! This of course left me a bit confused, but I’m pretty confident that I’ve figured out how Thunderf00t made his error. I actually found a clue at 21 minutes in, screen capped it, then tweeted my explanation.

He notes that a diesel semi can easily be loaded with enough fuel to go 2000 miles, while a Tesla semi with its battery at the limit, can only go 500 miles, which gives a coincidental factor of four. Does this mean the Tesla’s battery does not cause any payload penalty? Tesla has not released the figures for the weight of its semi or its battery. I think this made Thunderf00t a bit overconfident in his calculations. Now if Tesla would’ve given its semi something like a 1500 mile range, then it probably would have only a five ton payload (and cost about three times as much among other problems).

Now someone like Thunderf00t is obviously going to have a lot of online enemies so besides the glee of catching him with something this wrong, there are also going to be claims of dishonesty. They gave me an example where he had once made a claim that the space shuttle could stay docked to the space station as long as the Dragon capsule. Apparently the shuttle used fuel cells which only last a few weeks, while the Dragon has solar cells and batteries that can go on indefinitely. The arguments get into a bunch of hair splitting over whether the shuttle could be retrofitted with batteries and such. I did look it up and Thunderf00t did come back and defend his position, although some might argue that he was trying to weasel his way out. Thunderf00t’s factor of four payload miscalculation is more like scalping than hairsplitting, and I expect he will admit his mistake, although he hasn’t commented on it yet.

So does the Tesla semi’s battery cut into it’s load capacity? Thunderf00t has tweeted a video by a very articulate Australian automotive YouTuber who estimates it will cut the load by 12 to 20 percent. This guy’s pretty good and I’m having trouble filling this paragraph so I’ll post his previous Tesla semi video:

While Thunderf00t’s estimate of the payload penalty was wildly off, there’s still a significant penalty. Of course, payload and range are not the only potential problems for an electric semi. Early in his busted video, Thunderf00t shows a model S battery fire and how hard it is to put out. What kind of danger will this pose for a battery that’s ten times as large?. There’s also the question of how the electric infrastructure will handle new point demands for megawatts of recharging power. I also suspect there will be another roadblock in the form of mineral commodities inflation.

Despite all this, there are some advantages to electric trucks. They don’t emit air pollution where they are driven. Electric motors undoubtedly can deliver more power or torque than diesel engines. Regenerative braking saves energy and wear on brakes. I sometimes wonder whether there’s some sort of hybrid solution for trucking. Well, I’ll end with the two fanboys who seem to have found what looks to me like what might be an actual solution:


  1. The telling test would be a near fully loaded 40 foot containers. Google say the container rating is 26 tonne. I am not sure of highway load limits, but I thought for 18 wheeler it is about 36 tonne. Google says it is 80k lb and tare weight of diesel truck is about 30k lb. Taking a full container needs an overweight permit. If the new Tesla is much over that 30k weight, it can’t haul most of the big containers. Doesn’t limit it for many hauling jobs though, as most loads are lighter.
    What would be telling is the recharge time. If charge rate is say 100k,. that is massive cables, a lot of heat to dissipate and a lot of idle time for those trucks. There would also be the big draw on the grid – maybe they should only charge in California or South Australia in the middle of the day.


  2. What is it they say about the USA and the UK being two countries divided by a single language? In the UK a semi is a type of a house, not a lorry, but once I got into the article and worked out what was going on, I found it very balanced and interesting. Thanks, Mike.

    Despite what some might think (based on a lot of my comments about electric vehicles), I am not opposed to EVs in principle. I just don’t see them as the panacea that some seem to think they are. If I lived in a big city, had a garage where I could install a charger, and most of my journeys were short, I might buy an EV (assuming I could afford one). Like many issues, there are lots of pros and cons, and the subject isn’t black and white – a bit like climate change.

    Liked by 1 person

  3. I am afraid that I am going to lower the tone. Semi has another meaning and maybe some guys already have a Tesla semi from “Electric Jesus” as he is known.

    Seriously, range is more limited by permitted driving hours than fuel capacity. This is not a problem in Europe where one driver is the norm but maybe more so in the USA where having a second driver is more common on long hauls.

    Also it is necessary to consider not just gvw but individual axle loading limits. Cargo capacity is also limited by volume; if you are hauling boxes of cereal you probably come up to a volume limitation before a weight one.

    Liked by 1 person

  4. I posted this on another forum a week ago:

    “According to Autocar, Tesla will be rolling out 1 MW chargers for their Semi and intend to apply it to the Cybertruck as well:

    The firm claims the Semi has the ability to replenish 70% of its 1000-volt, 1000kWh battery in just 30 minutes. Although no battery size has been revealed for the Cybertruck, this could mean a full-charge time in just a number of minutes.
    The charging speeds, which will be the fastest ever available to the public, will be rolled out across Tesla’s supercharger network in the US next year, Musk said. It is expected to come to the UK with the launch of the Cybertruck next year.”

    That’ll dim the neighbours’ lights a bit!

    I’m wondering about cable size etc…..it could be like wrestling a python!

    Liked by 1 person

  5. John Cadogan’s two videos are very good at covering all the technical details of Tesla’s semi. Automotive journalists tend to be very good with colorful metaphors. I think it’s no coincidence that the late great PJ O’Rourke did a lot of work for Car and Driver magazine early in his career while he was honing his considerable rhetorical skills.

    Liked by 1 person

  6. Mike
    That 70% charge is a great factoid much exploited by the proponents. For Lithium batteries, they don’t like going below about 10-15% charge and going from 80-100% charge has to be done very slowly. That means the quoted capacity / range is a lot bigger than the practical ability. Their 1MWh drops to maybe 700kWh on the figures John quoted, that will knock about 250km off the range. For long haul, that is very significant.
    The other thing not addressed is with all the rapid charging, what is the battery cycle life? All the literature indicates it would be less than 100 cycles. So the whole battery pack would need to be replaced after 3 months!

    Liked by 3 people

  7. Mike, thanks for this post and your comment pointing to the irascible Aussie engineer-come-journalist John Cadogan. The allusion to PJ O’Rourke – I didn’t know of his early work for Car and Driver – worked for me and I watched the whole thing and learned a whole lot about ICE v EV. Well, I think. A little knowledge is a dangerous thing! Sorry that I didn’t take in the Musk fanboys so I no doubt only got part of the argument here. But Cadogan’s point about listening carefully to what someone isn’t saying is a key one for all journalists. And applies to Musk’s critics over Twitter, ironically enough.

    Liked by 1 person

  8. Chris M; certainly the fan-boys love these factoids. There is a bit of history of “over-promising” but that never seems to quench their ardour. For example, FSD (Full Self-Drive) has been a paid-for option for years but has yet to be delivered. A lot of people have handed over many $000s and are still waiting.
    Charge rates are one of the EV quirks which are not given enough airing. Adverts will quote headline figures but will not reveal the full picture, such as the time taken to add the last 10 – 20% – as you say. The key parameter is not the rate of charge; it is the time taken to add range. Some cars have a relatively slow max charge rate but can sustain it for longer than others with a higher rate.
    The website Pistonheads has a dedicated forum for EVs and alternative fuels. There’s a wealth of real-world experience which makes interesting reading, alongside a never-ending street-fight between EV advocates and opponents.
    Reading the threads, it’s clear that most owners avoid “thrashing” their batteries: they mostly charge – slowly – at home to take advantage of very low off-peak tariffs.
    Wrt to battery cycles, 100 is a very pessimistic figure. The Tesla Model S has been around for 10 years so there are a lot of high-milers which show relatively little battery degradation despite going through 100s of cycles. One of the advantages of EVs is that it is easy to check a car’s battery health and its charging history – although traders may not be forthcoming with the info!

    Liked by 2 people

  9. A first pass estimate is that each cable will be carrying in excess of 1000A. There’s some suggestion that the current density is 35A per mm^2. If so then the cables will need somewhere close to a kW of cooling per metre length. A 10m cable will need 10kW of cooling. Given the specific heat capacity of ethylene glycol (the supposed coolant) it will need to be pumped through the cable at around 1-2 litres per s to keep temperatures close to ambient.


  10. Some more details:

    The Semis will haul Frito-Lay food products for around 425 miles (684 km), but for heavier loads of sodas, the trucks will initially do shorter trips of around 100 miles (160 km), O’Connell said. PepsiCo then will also use the Semis to haul beverages in the “400 to 500 mile range as well,” O’Connell said.

    “Dragging a trailer full of chips around is not the most intense, tough ask,” said Oliver Dixon, senior analyst at consultancy Guidehouse.

    PepsiCo declined to share details on the price of the trucks, a figure that Tesla has kept quiet. Competing vehicles sell for $230,000 to $240,000, said Mark Barrott of consulting firm Plante Moran. He added that the 500-mile range Tesla Semi could be priced higher because its 1,000-kilowatt-hour (kWh) battery pack is about twice the size of many of its rivals.

    “We keep the trucks for a million miles, seven years,” O’Connell said. “The operating costs over time will pay back.”

    The Gatorade maker declined to share specifics on the weight of the trucks, another closely guarded secret by Tesla.



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