alt.hn

2/23/2026 at 10:00:58 PM

The Physics and Economics of Moving 44 Tonnes at 56mph

 https://www.mikeayles.com/blog/heavy-haulage-basics/

by mikeayles

2/26/2026 at 12:40:55 PM

> At 0.5 mph differential, the overtake takes 291 seconds — over a minute of blocking the outside lane. Annoying, but it gains the driver 5.0 extra miles across a working day.

The driver gets there 5 minutes earlier in exchange for causing a 7-km tailback multiple times per day? That seems like exactly the kind of thing that should be regulated away: the truck in front is limited to 90 km/h, you're limited to 90 km/h, you should expect to travel in convoy with that truck even through manufacturing tolerances mean your limiter is actually set to 90.5.

If the 0.5 km/h is actually valuable to the trucking industry, they can invest in more precise limiters at scale.

by dmurray

2/26/2026 at 1:02:14 PM

From a commercial perspective, you would think the fuel savings from slipstreaming would more than make up for those five minutes.

by RobotToaster

2/26/2026 at 1:26:16 PM

There's a diffuse, but I suspect large, economic cost to delaying other vehicles.

by HPsquared

2/26/2026 at 1:45:05 PM

> Most assume the truck driver is being inconsiderate.

From the article. Then goes on to show exactly how they're inconsiderate with maths. How they're not seeing it is baffling.

by matsemann

2/26/2026 at 2:25:58 PM

Seems to me that the slower truck is really the inconsiderate one here. If you’re already slower, tap the brakes a little and let the other guy slide in.

by cbdevidal

2/26/2026 at 2:48:27 PM

Or just take the foot of the pedal for a while.

by JoachimS

2/26/2026 at 3:41:26 PM

Or just step on the brakes. This will teach him about safety distance.

by hulitu

2/26/2026 at 6:08:40 PM

It kind of annoys me that the article says the people trapped behind the trucks are just inconvenienced, but the truck driver gains time and money. Considering commuting to and from work is what most people are doing on the road, that is exactly time and money. It really could be seen as truck drivers stealing dozens, if not hundreds, of minutes from other drivers to give themselves 5 minutes.

by 542354234235

2/26/2026 at 1:14:29 PM

> That seems like exactly the kind of thing that should be regulated away

This is regulated via "no overtaking by trucks" [1] signs on portions of road that are susceptible to formation of queues, or more dangerous road conditions.

P.S. To bundle some replies:

> but they only apply during busy hours

Don't remember ever seeing the time interval next to these signs. They are tied more to the location than the time. But that's not bad? The goal is to avoid the worst issues, not to force trucks to drive in an ordered line for 8h straight. Traffic lights also sometimes turn to intermittent yellow late in the night. Why spend a few minutes alone in the middle of the street for a red light?

> Does it still make sense for that to be "default allow?" Why doesn't the trucking industry lobby for every Truck Overtaking zone

The default should be the the one that applies most of the time. Today that's the "allow overtake". I'm allowed to very slowly overtake in my car. And I've seen this when I was driving right at the speed limit and someone else was overtaking at something like 1cm/s. It was painful to watch, at some point I just slowed down a bit to let him get in front and release the left lane.

If you ban truck overtakes and allow them only in specific zones, you'll quickly have kilometers long truck queues that never get drained. For an overtake that takes 1 min at 90km/h the trucks traveled 1500m. Many highways are 2 lanes so just one slow truck on the right lane and one slow car on the left lane screw the entire highway. Those costs go to you whether you're in your car or buying something those trucks deliver.

[1] https://media.gettyimages.com/id/1728143251/vector/no-overta...

by close04

2/26/2026 at 1:25:41 PM

Ahh, the power of defaults.

Does it (still) make sense for this to be "default allow?" Why not have the trucking industry lobby for every Truck Overtaking zone, instead of making residents lobby for the opposite?

by schiffern

2/26/2026 at 1:35:57 PM

I've also seen roads that have these kind of signs, but they only apply during busy hours.

However, as with any traffic controls they're useless if they're not actually enforced. Which is a shame, because it'd be absolutely trivial to automate that detection with cameras.

by entuno

2/26/2026 at 4:29:53 PM

>>That seems like exactly the kind of thing that should be regulated away

Yes, and the regulation should NOT be limiting passing or requiring the slower truck to brake

It should allow a "Push To Pass" button that allows a 10mph boost for enough seconds to make a pass in a reasonable amount of distance so as to not create problems for other traffic.

Current technology would allow these to be easily limited to X uses per hour/day and even geo-fence the usage for safe zones (use could even be limited to passing lanes so the truck being passed cannot start a drag race to stay ahead). They could even require connectivity and disable it in poor road conditions.

The real people being inconsiderate are not so much the truckers (particularly the slower trucker failing to yield and let the other one pass in a reasonable distance), as it is the regulators who created this mess.

by toss1

2/23/2026 at 10:00:58 PM

I was reading the NASA truck aerodynamics thread earlier and realised that commercial freight is one of those fields that touches everyone's daily life (everything you own arrived on a truck) but sits in a complete knowledge blindspot for most people.

I work in fleet fuel efficiency and wrote up the foundational mental model, covering why trucks weigh what they weigh, why they're all doing exactly 56mph, why diesel is so hard to replace, and why 1% fuel savings matters when you're burning 43,000 litres a year.

This is the first in a series, there's already a 2-part deep dive on hydrogen up as well. Tried to keep it accessible without dumbing it down.

by mikeayles

2/26/2026 at 12:40:40 PM

this is well written. thank you - you broke down the economics nicely.

I do think maybe with a hub & spoke model - big trucks move loads to hubs -- then smaller electrified trucks cover the less than 200 miles from hub to spoke. electrified smaller trucks and vans are already economical today.

you get to benefit from using diesel for long haul routes - while also - better economics on the electrified front i.e a hybrid model

by dzonga

2/26/2026 at 9:18:50 PM

And I'd rather have last-mile trucks with Direct Vision, no blindspots etc driving around city streets, backing into stores etc., than huge 44 tonne long haulers that can maul pedestrians in an instant.

by matsemann

2/26/2026 at 1:34:42 PM

The cost to load/unload a truck becomes the main expense if you move it too many times.

This is why LTL shipments can be a significant fraction of just sending an entire container, and that's assuming they're still palletized.

by bombcar

2/26/2026 at 12:52:31 PM

Trains for longer distances and then electric trucks for last mile

by newsclues

2/26/2026 at 3:43:33 PM

Maybe there are ways to make that faster and cheaper now with more computers and automation.

by ahartmetz

2/26/2026 at 12:49:35 PM

A very well written article! I'd add a few things though.

> Every kilogram you add to the vehicle is a kilogram you can’t carry as freight.

That is only relevant when hauling bulk loads, think ore, soil and the likes, or you're carrying a trailer full of IBC liquid containers. I worked in stage lighting stuff, our trailers were at least 3/4 foam by volume, they didn't even come close to maxing out their weight.

> A battery pack storing equivalent energy would weigh on the order of 16 tonnes at current lithium-ion energy densities.

You don't need to haul a fully equivalent battery. Drivers have to have their mandatory rest breaks of 30+15 minutes here in Germany - that's enough to charge 300-400km of range. Additionally, they can be charged at loading docks, provided the freight base or the customer have chargers set up.

> For a driver paid by the mile, or on a delivery schedule measured in minutes, that overtake is rational.

Payment by mileage is illegal in Germany, as a trucker you need to be paid by the hour and you need to be paid under German minimum wage law as long as you're physically on German roads. Trucker companies from Eastern Europe are infamous for evading that, but as our customs enforcement (who also do the road inspections for rest breaks and minimum wage) ramps up, it's getting better.

The remaining problem are the dispatchers, quite a few of them hand out routes to their drivers that are barely achievable when operating legally (i.e. trucks with working speed governors, drivers taking their rest breaks). Competition is fierce, there used to be talks about passing laws to force dispatchers to not give barely-legal orders but I'm not sure where these went following our government's collapse last year.

> An electric drivetrain achieves around 90%, so you only need roughly 1,600 kWh of battery capacity for equivalent range.

Yup, and most importantly, you mentioned regenerative braking cutting down on brake wear - but it's not just cutting down there, the truck can actually save a fair amount of energy as well, at least outside of highways where the truck is mostly just coasting along.

Trucks, given the right infrastructure, are also viable for running them electrically in the mid-range nowadays as a result.

by mschuster91

2/23/2026 at 10:23:04 PM

Really interesting. Much thanks!

by allears

2/26/2026 at 1:32:12 PM

Do you have an RSS feed for your blog?

by kqr

2/26/2026 at 1:45:37 PM

I do now: https://www.mikeayles.com/rss.xml

by mikeayles

2/26/2026 at 5:10:14 PM

NetNewsWire can't find that feed.

"Can’t add a feed because no feed was found."

I used the RSS validator at w3.org

https://validator.w3.org/feed/check.cgi?url=https%3A%2F%2Fww...

This feed is valid, but interoperability with the widest range of feed readers could be improved by implementing the following recommendations.

line 1, column 10821: Missing atom:link with rel="self" [help]

... category><category>Web</category></item></channel></rss> ^

by jdeibele

2/26/2026 at 2:07:26 PM

This is excellent, I'm really looking forward to your piece on fuel additives.

by jcgrillo

2/26/2026 at 1:12:42 PM

For people that want to make the calculation: A truck does not need a 15 ton battery. In Europe, we have mandatory breaks for truck drivers. So you need a battery pack for max 400km of range, let's say 500km. When you have a break, you charge. For this, you need like 1500kWh battery pack, which weigths like ... wait, 15 tons. But this is not entirely correct, the real values reported are between 120-150Kwh/100km, that means a half of the stated number, 7.5 tons for the battery pack.

by secult

2/26/2026 at 2:25:02 PM

Those mandatory breaks are 45 minutes long. You're not charging 750 kWh in 45 minutes. With a fast charger 750 kWh is 2 to 7 hours. At the far more common level 2 chargers it's 18 hours. Either mandatory breaks need to be substantially longer, you need a substantially larger battery than just that required to go between breaks, or you need some sort of specialized technology for dramatically speeding up charging rates well beyond those for personal EVs, any of which cut hard into the economics.

by jjk166

2/26/2026 at 2:58:12 PM

Tesla is, in theory, deploying a handful of 1.2MW charger sites: https://electrek.co/2026/02/24/tesla-megacharger-64-location...

Assuming some amount of tesla over-hyping there, Tellus is doing 600kW chargers: https://chargedevs.com/features/inside-tellus-powers-600-kw-...

So _if_ your route had those, you could charge in somewhere around 1.25h. Not enough for break time, but you can imagine starting with, say, a 1.1MWh battery with one +500kWH boost mid-day being enough to get you to an overnight full recharge. Lots of "ifs" there, since you might not always be able to get full charge rate from the charger, might not time things perfectly, etc., but it doesn't seem completely out of scope for a few years from now.

(And who knows, perhaps tesla will come through with those megachargers. Seems more likely than, say, building an autonomous humanoid robot.)

by dgacmu

2/26/2026 at 1:22:03 PM

It’s weird that he’s so in the numbers but then doesn’t carry through with the battery electric truck calculations. He just dismisses it out of hand.

Your cargo may be reduced but your fuel costs will also be reduced. It’s quite a complicated calculation.

Are you hauling sand? Then you probably can’t spare a single kg of cargo limit. Doing LTL work? Then maybe you’re not totally filled anyways. It really depends. If you’re fine with a 35 ton limit you might be able to make good money with the fuel savings.

by torpfactory

2/26/2026 at 12:47:50 PM

> This isn’t advisory. It’s a physical limiter in the engine’s ECU. The truck cannot go faster.

I live in Latvia (in the EU) and see a significant part of our ARTICs on the roads go well past 90km/h daily. I presume their fleets do monitor the speed and alert the driver if speeding for a prolonged period of time but they are obviously not physically limited. Maybe the limits do come from the factory but get disabled? I really couldn't say.

A recent journalistic investigation uncovered a problem with the weight limit not being followed on a mass scale too. Specifically by our lumber industry whos drivers are incentivized to break the law. Even if you see a dangerous overloaded truck on the road and call the Police, it is likely no action will be taken because there only a couple of units in the country that are equipped to weigh a freight truck out in the field.

by NomadicDaggy

2/26/2026 at 1:03:37 PM

Probably the first thing to consider is the trucks have their speed calibrated periodically to ensure the accuracy of their tachographs (in the UK at least) so a truck doing 90kmph may show as 100kmph+ in a passenger car, I know my Volvo is 7% out, and my Seat is closer to 10% out.

That said, depending on the truck, there's fuses you can pull, ECU remaps and even for the older trucks with the magnetic sensor in the gearbox, the trick is/was to stick a magnet on the sensor (with a bit of string, so you can pull it off remotely if you get pulled over). All of these methods are becoming less feasible, as things like the aggregate wheel speed sensors used for ABS get used, you can't just fool one thing now.

As for the weight limit problem, that's a whole other rabbit hole!

by mikeayles

2/26/2026 at 2:03:16 PM

Cant they divert them to a nearby weigh bridge and find out?

by aitchnyu

2/26/2026 at 1:41:11 PM

Tachographs are mandatory and monitored across the EU so I very much doubt that's really happening.

by izacus

2/26/2026 at 4:14:32 PM

Just because something is mandatory, doesn't mean it's enforced. You got 6 million trucks registered in the EU alone [1], plus fleets of trucks registered in adjacent states such as Turkey or Serbia, or old trucks out of the new Eastern European states that predate their EU membership and, with it, mandatory governors. And loggers can be manipulated as well, if you do it right there is no chance of finding that out without taking apart the truck.

Not every country is as thorough as Germany is in technical inspections, trucks from outside the EU don't need speed governors, and as long as you don't race your truck in Germany, France or Austria, chances are high no one will be bothered enough to pull your truck over for a detailed inspection on an examination wheel. Or you simply have two datalogger cards, that you swap out when going into one of these countries.

[1] https://trans.info/de/eu-lkws-alternde-flotten-449472

by mschuster91

2/26/2026 at 1:42:17 PM

The (bad) justification for overtaking seems a much better justification for the slower truck to fix their calibration and go faster.

Lots of good info but it all feels a bit like it is being used to create a "just so story" to support whatever the current status quo is.

by ZeroGravitas

2/26/2026 at 1:51:20 PM

Right. If 0.5 mph is so valuable (which I believe), how do we explain the slow trucks? How do we fix the slow trucks?

by schiffern

2/26/2026 at 4:19:53 PM

IIRC, the difference in radius between fresh tires and those worn down to just before they need replacing, changes the actual speed at any given speedometer reading by about 2%.

C=πD and all that.

by ben_w

2/26/2026 at 12:36:16 PM

Argh the liberal admixture of different units (mpg, kg, L, hr) in the first table really brings home that this is a UK piece.

by gerikson

2/26/2026 at 2:52:15 PM

Also the mpg figures are almost certainly “metric gallons”, 4.5l.

US gallons are 3.8l

by testing22321

2/26/2026 at 6:58:59 PM

Maybe they should give the trucks a "turbo boost" button that lets them increase speed by something like 5 KM/hr for 120s every 30 minutes. Just enough to allow truck drivers to pass now and then without causing these types of log-jams on the highways, without causing safety problems. I'm sure there's a more correct combination of speeds and times than this.

Sort of like the silly "boost buttons" on the Honda CR-Z [1] or the Elantra N [2], but just lifting the speed limiter for a bit...

[1] https://en.wikipedia.org/wiki/Honda_CR-Z#Powertrain

[2] https://en.wikipedia.org/wiki/Hyundai_Elantra#Elantra_N/Avan...

by yabones

2/26/2026 at 2:03:55 PM

Interesting, thanks!

One thing I'd update is that early in the article you say that for switching from diesel to lithium-ion, "It's 16 tonnes of payload that disappears".

But then later you take engine efficiency into account and say it's "about 6.4 tonnes of battery".

So the claim that it would ever reduce payload by 16 tonnes seems incorrect, and not everyone is going to read both parts.

by hrldcpr

2/26/2026 at 1:49:46 PM

> Rail is superb for what it does: moving bulk commodities... The problem is last-mile.

Before around 1950x-1970x rail networks were more dense (at least in Europe) - any significant goods source/destination (like a warehouse, a factory e. t. c.) had a railway spur. Lots of rail tracks / spurs were abandoned /removed when it was widely believed that trucks are the future and railways are outdated.

If all these spurs were kept last mile problem would not be as bad for railways. Also electric trucks are well suited to solve this last mile problem.

by citrin_ru

2/26/2026 at 4:46:03 PM

I think they gloss over a major factor also. They mention:

> Distribution centres are built around motorway junctions (J24 of the M1, the Golden Triangle in the East Midlands) because that’s where road access is.

But they skip _why_ is that road access and motor junction there. It's there because the government decided building roads was something that was it's responsibility. I know this article is UK focused, but for the US if the government decided to build rails also, then they could put them in more convenient places. Instead they allow rail companies to decide which monopoly corridors the companies get to control.

by conscion

2/26/2026 at 2:56:48 PM

The article makes it sound like the Tesla Semi is physically infeasible. Yet, it is in active use on a sufficient number of long-haul routes that ignoring this proof of existence undercuts some of the central points the post tries to make.

The combination of higher efficiency, regenerative breaking, and some regulatory wiggle-room such as slightly higher allowable gross-weight (2000 lbs in the US, and 2000 kgs in the EU), together with reduced maintenance cost and time significantly affect the economics of trucking.

As regulatory frameworks price in more externalities of internal combustion engines, such as the climate and health effects of their emissions, burning diesel will no longer make economical sense. All road transport will end up being battery-electric. The declining cost of owning and operating electric vehicles compared to internal combustion ones will reach this point even without regulatory changes, just at a slower pace.

by GeertB

2/26/2026 at 12:39:49 PM

Is this correct — HGVs can go faster on dual carriageways than motorways?

"UK speed limits for heavy vehicles are also more complex than most car drivers realise. Articulated trucks over 7.5 tonnes: 60 mph on dual carriageways, 50 mph on single carriageways, 56 mph (limiter) on motorways"

Not able to find a source that verifies that

by A_Duck

2/26/2026 at 12:45:16 PM

Sorry, got mixed up there, will amend, the 60 is for +3.5t!

Edit: Nope, despite the vehicles only being able to propel themselves to 90kmph, the speed limit is indeed 60mph (in England and Wales, Scotland is a more sensible 56mph)

https://www.gov.uk/speed-limits

by mikeayles

2/26/2026 at 2:38:44 PM

Long haul trucking should be illegal or effectively eliminated by a carbon tax. Use trains for long hauls.

He even said the problem with trains is last mile. Last mile short haul trucks can be and are electric.

It's weird he laid the groundwork for this argument, but he isn't making this argument.

Fix the infrastructure issues that make transferring from rail to truck difficult. Yes, that's challenging and expensive. Guess what else is? The status quo, and the effects of climate change.

by mcdonje

2/26/2026 at 1:31:39 PM

> The five minutes of inconvenience to you saves them meaningful time and money over the course of a day.

Assuming my time and everyone else stuck behind them combined is far less valuable than the truck driver.

by Steve16384

2/26/2026 at 12:58:35 PM

>Most assume the truck driver is being inconsiderate.

You could probably add a whole section of specifically learning to drive a car with trucks on the road to driver education programs and it would do wonders for traffic.

>Anti-idle ordinances exist in several US states and EU regulation is moving in this direction.

Yep, grab a sleeping bag or take your clothes off and use evaporation cooling on yourself. The good news is that car/van camping stuff can apply to trucking as well and that is fairly popular these days.

Another option is simply having places to sleep outside of the truck that are powered by solar/wind and don't cost anything to truckers, but that's only viable when we actually care about reducing emissions over profit.

>Every kilogram you add to the vehicle is a kilogram you can’t carry as freight.

You can save a bunch of weight by not having the sleeper cab if you can readily stop somewhere for a safe place to sleep. There's quite a bit of frontier savings you can do by externalizing costs of transporting stuff to other industries (aforementioned free hotel rooms) and getting tax payers to pay for it, which makes a ton of sense here since trucks are transporting all of the food we eat.

by hnthrow0287345

2/26/2026 at 1:35:48 PM

> Yep, grab a sleeping bag or take your clothes off and use evaporation cooling on yourself.

Talking about driver education, refrigerated trucks never get to turn off the engine until they unload the cargo. So it's not always for comfort.

> if you can readily stop somewhere for a safe place to sleep

That's the missing infrastructure. Drivers pull over to sleep when they hit their daily driving limit and in Europe most of the places to pull over are plain old parking lots maybe with some services like a gas station. Motels are relatively uncommon. I think losing some of the driving day and paying for a motel more than make up for the benefit of a lighter cab.

by close04

2/26/2026 at 4:12:49 PM

Talking about driver education, refrigerated trucks never get to turn off the engine until they unload the cargo.

The refrigeration unit often runs on a separate unit powered by its own engine, not the engine powering the truck. Don’t get excited just yet, as those engines do not run clean. They do use less fuel than the truck’s engine, though.

by mikestew

2/26/2026 at 12:35:26 PM

Why is fuel consumption 5x more per mile but 10x more per hour, if the trucks are moving more slowly than cars?

by dmurray

2/26/2026 at 12:52:22 PM

Yeah the numbers in this article are all over the place. "291 seconds" also got rounded off to "over a minute", when it's closer to 5 minutes

by gruez

2/26/2026 at 1:17:21 PM

Good spot, and gruez is right about the caption too (fixed both, thanks).

The car's L/hr figure was wrong. At 45 mpg (imperial) and 70 mph cruise, a car burns ~7 L/hr, not 3. That makes the flow rate ratio ~4x, which is consistent with 5x per mile and the truck travelling 20% slower.

The ~3 L/hr I originally had is what you'd see as an average over a mixed driving cycle — ~30 mph mean across urban, suburban, and motorway. I was carelessly mixing the cars combined-cycle flow rate with the truck's cruise-only figure in the same row.

The truck doesn't have this problem because a long-haul artic genuinely spends most of its operating hours in that narrow 50-60 mph cruise band. "Average fuel burn rate" and "fuel burn rate at cruise" are nearly the same number. For a car they're very different, transient acceleration, idling in traffic, and low-speed urban driving all drag the average flow rate down well below the motorway figure.

by mikeayles

2/26/2026 at 1:10:05 PM

That is simple, that one (very cool) interactive matrix only has that one output description regardless of the input. The effect is clear either way

by Reubachi

2/26/2026 at 2:09:02 PM

Tangential, do vehicles detect motion by crosswind or road camber and compensate? I saw some social media post of lots of trucks toppled over by crosswind.

by aitchnyu

2/26/2026 at 3:58:28 PM

Our camper van (which is a tall sail) compensates for sidewinds. Other RVs can have this feature as well, though often as aftermarket fitment. Pretty neat when it works, “man, sure is windy today, but this van is a lot easier drive in the crosswind than our old RV. Oh…”

But an RV is not a semi tractor-trailer setup. In fact, crosswind compensation is something I’ve only seen on RVs that don’t involve a trailer (Class A, Class C). And for a semi, how much is in the trailer? Seems a compensation system would need to know that.

by mikestew

2/26/2026 at 7:41:54 PM

Seems very integrated into the vehicle. Who is selling aftermarket versions?

by aitchnyu

2/26/2026 at 9:18:00 PM

I'd swear I've seen such systems advertised in the appropriate magazines for large RVs (Class A "tourbus" RVs), but for the life of me a web search brings up nothing. For now, assume I hallucinated such a thing (or maybe what I think I saw was actually just an old-school steering stabilizer that advertised "crosswinds!".)

And you're right, it does seem that the systems are integrated. For example, Mercedes' system for the Sprinter applies the brakes on one side to compensate. Seems like something would need to tie into the CAN bus to pull that off. Not that aftermarket couldn't do the same, but is that functionality even available on a 43' pusher diesel?

by mikestew

2/26/2026 at 12:59:28 PM

great article but the 44 tonne limit is not "physics", it is regulation. if an electric truck would be allowed to weigh 5 tonnes more all these calculations would be different.

by dinkblam

2/26/2026 at 1:27:21 PM

The regulation is at least partially informed by physics though.

Braking distances, road damage (scales with the fourth power of axle weight), bridge limits, etc.

If the limit could safely and appropriately be 49 tons for diesel trucks right now, it probably would be.

by sokoloff

2/26/2026 at 1:19:00 PM

How is fuel consumption per mile 5x but fuel burn per hour 10x?

by CarVac

2/26/2026 at 1:35:37 PM

>. That’s roughly 28 to 35 litres per 100 km, or around 30 litres per hour at cruise speed. This is not a misprint. A truck burns in an hour what a small car burns in a week.

Let me paraphrase - a truck weighting 25 times more than a car burns only 4 times as much fuel per 100km at corresponding cruising speeds.

> At 0.25 kWh/kg, that’s still about 6.4 tonnes of battery — roughly 18 times heavier than the 350 kg diesel tank and fuel it replaces, and 6.4 tonnes of payload that disappears from every trip.

And how many tonnes of internal combustion engine, gearboxes and plumbing? It is not an insignificant matter

by ReptileMan

2/26/2026 at 2:19:30 PM

A Cat 3406 weighs around 4000lbs and an Eaton 18spd weighs around 1000lbs. So rounding up a bit for accessories and other equipment say 6000lbs total (~2750kg).

by jcgrillo

2/26/2026 at 2:29:48 PM

throw 350 kg of diesel. So the extra weight is 3 tonnes, not 6. Not peanuts, but I think it is manageable and the math could work, especially if they charge on off peak or surplus electricity.

by ReptileMan

2/26/2026 at 2:36:59 PM

A diesel electric hybrid, at least naively, makes quite a lot of sense to me. Your generator can be sized such that at full output at its torque peak it's making enough power to push the truck at highway speed up a slight incline (just slightly overpowered for maintaining highway cruise). Batteries take up the slack for starting, pulling hills, etc. Remains to be seen whether it actually works.

by jcgrillo

2/26/2026 at 1:58:55 PM

> A diesel fuel tank for 400 litres of diesel weighs roughly 350 kg (the tank itself is relatively light; diesel is 0.84 kg/L). A battery pack storing equivalent energy would weigh on the order of 16 tonnes at current lithium-ion energy densities. That’s not just additional weight. It’s 16 tonnes of payload that disappears.

And yet, electrical semis exist that come without 16 ton batteries. The fallacy here is that most of the diesel is used to heat the universe rather than move the truck. Truck engines are relatively efficient but it's still a combustion engine. EV trucks are now a reality.

Mercedes-Benz’s eActros 600, one of the flagship battery-electric long-haul trucks now in series production, uses *three 207 kWh LFP battery packs for a total of 621 kWh of installed capacity, and under realistic conditions can deliver about 500 km of range on a full charge with a 40-ton gross combination weight, with opportunity charging in driver breaks enabling well over 1 000 km of daily travel. That's 4-6 tons of battery, not 16.

Volvo Trucks’ current flagship, the FH Electric, has 360–540 kWh of batteries (four to six packs) and achieves up to ~300 km of range for typical heavy-duty operation, and its forthcoming FH Aero Electric long-haul variant is being announced with ~780 kWh battery capacity targeting ~600 km of range. That's around 3 tons of battery.

The weight goes at the cost of the useful load. Though the EU allows an extra 2 tons for new energy trucks. And of course a lot of trucks aren't fully loaded typically. Also, the weight limitations have a lot to do with safety issues related to diesel trucks and their brake systems that electrical trucks have much less. Regenerative braking and lots of torque at low speeds mean that they could move a lot more weight safely than currently allowed. And adding more axles to distribute the weight can address any road damage concerns.

With mandatory 45 minute breaks every 4.5 hours, trucks can just top up as needed. With normal truck driver hours that's 1 or 2 breaks in a working day. There's a growing amount of chargers all over Europe and these things routinely drive all over Europe from Scandinavia to Iberia to Balkans and everything in between. There are of course still many places where more/better chargers are needed but these ranges are usable and practical enough that you can get loads from A to B in most of Europe with only minimal delays relative to diesel trucks in terms of charging time losses. It's early days and charging infrastructure is rapidly being improved. But the point is, that electrical trucks work just fine today. There are no fundamental real load or distance limitations here. But of course more infrastructure is needed to scale.

Lighter batteries will make trucks slightly more efficient. But price and longevity matter much more. Sodium ion with its well over a million mile lifespan looks like it should revolutionize trucking over the next decade. LFP is commonly used today already. NMC is lighter but has a lower lifespan.

by jillesvangurp

2/26/2026 at 2:46:41 PM

Fantastic comment, thanks! A review of the state of BEV's was actually going to be one of my next articles (hopefully after the additives).

Are you happy for me to drop you an email to review a draft when I'm ready?

by mikeayles

2/26/2026 at 4:20:30 PM

sure, please do

by jillesvangurp

2/26/2026 at 1:48:57 PM

the one being overtaken could release the throttle for a moment...

THE ONE BEING OVERTAKEN COULD RELEASE THE THROTTTTTTLE...!!!

:)

by attila-lendvai

2/26/2026 at 2:37:36 PM

Yeah, except then they would lose 10 seconds from going 54 mph instead of 56 mph...

by sobjornstad

2/26/2026 at 12:48:08 PM

.

by schiffern

2/26/2026 at 12:50:06 PM

They mention this later in the article. It's still about 6 tonnes for the battery to store as much effective energy as the diesel tank.

by WJW

2/26/2026 at 12:53:21 PM

It seemed like the author had moved on from EVs so I thought he was done, but okay. Should've finished I guess.

The article still never accounts for the fact that motors+inverters are ~2 tonnes lighter than an engine+transmission.

by schiffern

2/26/2026 at 12:58:20 PM

Or your reading comprehension is not good enough. I didn't have any problem finding the paragraph where he author goes into extra detail. Who can say.

by WJW

2/26/2026 at 12:50:25 PM

They are addressing that a few pages further down.

by mschuster91