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Comment by cesaref | Hacker News Reader

Pounds, feet, horse power and millilitres are used in one sentence which makes my head spin.

Here's the same press release written in metric land:

https://www.autodaily.com.au/koenigsegg-designs-in-house-ev-...

It's good that people are getting the weight down of these motors, but i'm still unsure why I need 250kW+, let alone two of them built into the drivetrain.

I've managed with <100kW for the last 30 years in my cars of choice, and I know headline figures sell stuff, but we're trying to save the planet at the moment. But I guess if it convinces petrolheads that there's still fun to be had going electric that serves a purpose...

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You most certainly are not in the target audience for anything Koenigsegg makes. Maybe a handful of HN could have the finances.

YC 2023: buying me a Koenigsegg

Although it’s worth noting that “trickle down” tech advancements are quite a powerful force in the automotive industry

Unlike internal combustion engines, an oversized (for everyday driving) electric motor is not substantially less efficient in everyday driving than a normal-size one. In fact, oversized components are often more energy efficient (less electrical resistance etc).

i've always had the impression that miniaturization was the key to low thermal dissipation and electric consumption... How is it different with motors ? ( genuine question)

An oversized motor will be slightly less efficient at low load, but only slightly (compared to an IC engine whose efficiency is strongly related to size).

An oversized battery, or oversized wiring, will generally be more efficient due to reduced resistive losses. Larger components (such as are designed to handle high power levels) have lower electrical resistance.

(Resistive heating power) = (current)^2 * (resistance)

Since you seem pretty knowledgeable : how can i reconcile two observations that seem contradictory to me :

- "smaller" cables in CPU make for lower energy consumption

- "larger" cables in engine reduce resistance

Most of the places where miniaturisation is key to low power consumption are where power is used to process information. In that case, you're trying to get the amount of energy required to handle a bit flying past as small as possible. Most of the energy consumed in this way is used to fill up or empty the capacitance of the "wire" leading from the output of whatever is processing that bit of information, so anything that reduces the capacitance will reduce the power consumption (to a point - you also need to worry about leakage). Miniaturisation reduces that capacitance.

With electric motors, it's completely different - the amount of physical work that comes out of the motor is fixed - you can't reduce it like you can with information processing. So, you're purely looking at improving the efficiency of the conversion from electric power to mechanical power. A larger motor allows you to do that with thicker wires (so less resistance to heat up) and with things moving at a slower speed inside (which also helps). The only downside of a larger motor is if you have to carry it with you - that could reduce your efficiency by making the vehicle heavier. However, electric motors are generally remarkably efficient these days, and the main consequence of the inefficiency is heat generation, which gives us the other advantage of making it bigger - it is easier to dissipate heat from a larger object than a smaller object.

Energy efficiency is usually expressed as a percentage in one of two forms:

1. (useful energy out) / (energy in)

2. (theoretical minimum energy consumption) / (actual energy consumption)

In thermodynamic systems the second is often expressed as "isentropic efficiency" or similar.

In computing the second term can also be expressed using Landauer's limit [0], the theoretical minimum energy consumption of computation. Current computers are still shockingly inefficient in this regard, taking several orders of magnitude more energy usage than the "ideal" minimum.

So really, as inefficient as a gasoline engine is, it's nowhere near as bad as even the smallest, most modern CPU.

"Millions of times" level of inefficiency is like burning banknotes for warmth.

https://en.m.wikipedia.org/wiki/Landauer%27s_principle

Koenigsegg makes super cars. These motors are not for you.

Not that you're wrong generally speaking, but doesn't Koenigsegg R&D and license technology too? I believe they're trying to license (maybe even manufacture) their freevalve technology to some ICE-based auto manufacturers?

So it's certainly true that most of us here probably aren't the target for Koenigsegg super cars, we might be indirectly consumers of the engines or engine technologies they create.

Koenigsegg has been an incredible company to follow and their CEO is such a pleasure to listen to that they're one of the few auto companies that I'm excited about. I'd be even more excited if they took a path similar to Tesla or Polestar and started offering an affordable brand of EVs.

There is one positive environmental aspect of high power electric motors if they are capable of recuperation: you can recuperate a larger portion of the kinetic energy which would be wasted otherwise as heat using breaks. This counts even for heavy cars running lower speeds or not accelerating fast.

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