alt Hacker NewsThis would only make sense if the EV efficiency gain were due to lightness of the vehicle or better aerodynamics. It's definitely not the first, and don't imagine the second is a big factor but maybe I'm wrong. I'd even expect EV to help here because a heavy trailer takes more energy to get moving that can be partially recouped when regen-braking.
Is it just that these EV trucks don't have multiple gears to tune themselves for towing? Like how many EV cars are geared for city speeds but suffer on the highway. I know dual-motor ones have different ratios, but that's still 2 speeds vs 6-10. Edit: Could also be about engine tuning.
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A large amount of the energy of an ICE is wasted as heat and noise. Some of that is a constant factor that isn't sensitive to load. So when increase load, it doesn't make as much of a difference to energy used.
By contract in EVs, much more of the energy is going towards moving the vehicle and therefore both weight and air resistance greatly affect the amount of energy use.
You can’t recoup the braking energy when the trailers have their own brakes.
The second is in fact a big factor. The vast majority of a car's drag is aerodynamic drag since it grows quadratically with speed; rolling resistance and stuff are much smaller at highway speeds. In order to compensate for the tiny capacity of batteries, EVs try really hard to squeeze out better efficiency in aerodynamics and other sources. That's why EVs have flush door handles and stuff.