There's also that electric cars have a marginally better drag coefficients for a few reasons - ICE vehicles have a bot less incentive and they need to use more air for cooling - so the drag from a trailer will be worse, as a percentage extra, on the average electric vehicle.
Of course an ICE uses more fuel in absolute terms on a higher load than a lower one. But the proportion of fuel wasted compared to fuel turned into propulsion improves as load is increased (at least up to a point, maybe not all the way to absolute maximum load).
Electric systems also have efficiency curves, but they are less drastic within the primary load range.
* cylinder filling is more efficient at maximum output request (on naturally aspirated engines operating in vacuum, due to less simple pumping loss, on turbocharged or supercharged engines, due to less wasted energy producing charge air and generally more optimized air/exhaust exchange). in short, air gets into the cylinder more efficiently in the first place at high torque requests
* combustion is more complete at high cylinder filling; not only does more air get into the cylinder, but it also burns more completely
* friction losses matter less at higher torque, especially on larger engines
Almost every ICE complexity advancement over the years is to hack around these basic properties: VVL and VVT to optimize pumping, direct injection, stratified injection, and dynamic compression hackery to get around cylinder filling efficiency, and cylinder deactivation / variable displacement to avoid friction and pumping loss from unnecessary engine size. but while ICE engines have made huge strides, they're still more efficient when they're loaded.
And note that this is efficiency, not absolute consumption - of course you'll consume more at higher load still, but the ratio is better. Combine this with the aerodynamics of most ICE pickup trucks and you have a scenario where ICE trucks frequently lose very little fuel economy / actual consumption when towing a trailer.
But boy does my model Y tow tiny trailers well.
It takes about 3 minutes to add 350 miles of range to my gas vehicle.
In my little commuter car with a 40l tank the fastest I’ve ever filled up was 6 minutes.
Generally this is only true for ICE with an abundance of extra power to start with, but that is basically every truck and most other cars for the last 25 years.
I frequently tow between Washington and Montana, and I only have to fill up the F-350 once or twice when loaded. You would need to recharge a loaded Cybertruck 5+ times on that same route. My 11 hour drive just turned into a 15 hour drive in ideal conditions. And I don't think there are the latest superchargers available on most of the route, so the time spent charging is likely much higher.
Don't get me wrong, I like EVs and have a Model 3 as my daily driver. But I would never get rid of the gasser given today's battery tech with the number of roadtrips we take.
But... why? Like, at that point it should make more sense shipping whatever freight you want to ship by train?!
Locally farmers built a rail to port system as a grain carriage has more tonnage than a road train.
Two axle trailer is it? What's that max out at, two tonne?
Yes, clearly there are cases when it makes sense to ship by train, otherwise they wouldn't exist. I can't tell if I'm not getting my point across, or you just want to be pedantic, but the point is that most people who own the capability of transporting something, will transport it themselves.
I did specifically ask about your trailer - not a generic set of trailers, but, okay.
What I'm getting is you don't have a prime mover actual truck with one, two, or three trailers to tow single or in a road train.
> the point is that most people who own the capability of transporting something, will transport it themselves.
to some degree but by no means always, sometimes it makes sense to have others do transport while getting on and doing others things in the same time.
> or you just want to be pedantic
Just familiar with transport, a great deal across a remote state 3x size of Texas, and a fair amount to other parts of the world, by air and sea.
Because the numbers are a bit off. I've towed a lot, gas trucks do not lose 15% when towing. My old F150 went from 18mpg to 10mpg. My super duty went from 16mpg to 8mpg.
The advantage is that gas is so energy dense we just routinely equip trucks with 35+ gallon fuel tanks. There's no battery option equivalent yet.
An ICE vehicle isn't less efficient because it takes more energy to move, it's less efficient because the engine is inefficient, burning off a high percentage of its energy as waste heat.
But that will be true regardless of what the load is. If the ICE truck takes 5 units of energy to pull itself compared with 1 unit for the electric car, that implies that the the truck only actually requires 1 unit to pull, but the ICE engine burns off 80% of its energy as waste heat. The engine is only 20% efficient.
Now if you start pulling a trailer, you have (in total) 2 units of energy worth of load. But if the ICE engine is still only 20% efficient, then it will take 10 units to pull both, rather than 6.
I can believe that this effect is real (electric cars suffering more range loss when towing), but it seems to require an explanation beyond this one.