Hi Grey!

I understand what you are saying about a power mode versus economy mode and the gimmicks played to make a feature out of it.

In days of old an ordinary vacuum gauge it does the same thing.
The higher you can the vacuum up in the manifold, by not opening the throttle for less incoming air,, the less fuel mixture the engine got. Too simple of a concept I guess?
Between looking at a gauge they have tried lights, buzzers or just refuse to let it shift down or up.

Make it so it’s not put it under a brainless foot would be the place to set it up.
Don’t over build the engine size and under build the transmissions.

We are just now getting the idea across with nine and ten speed transmissions.
But the yo-ho’s, on both sides of the aisle, keep marketing horsepower numbers for low times in accelerations to the next traffic light!
Then there are engine gimmicks to shape a power curve, in an already inefficient energy conversion device, for about 120 years!

I have been on this planet since it’s inception and until evolution popped me out, 72 years ago!
Like everyone else I have seen the sun’s photons beating on our heads and electricity staring us in the face yet for the last forty years we are still willing to “sniff” them without doing better.
Color “US” humans as “all” being slightly dumb and a bit more LAZY!!

I just remembered you asked a question about why the term “common” is used in electrification.
The term should only be used when working with Alternating Current circuits because it uses phases!
The phases rise and fall in relation to a zero point per circuit.
I the generation of AC there are three circuits traveling out of a dynamo.
Of those three outputs, at any given time one phase is in rotation to be zero and the other will be opposite but they are still in common to the same dynamo's!
All the dynamo's circuits in a grid have to be kept in synchronization and so we are watching the “commonality” of those phases!
When starting upon an auxiliary power generator we have to have the generator up to speed and timed to a common phase.
Those high voltage or “Tension” towers you see across the land are carrying three phases on each side.
One side can be shut own for maintenance while not interrupting the system as a whole!
Again common is to be used only in AC!

DC or “Direct” Current is only positive or negative.
If you have a junction of one side you have a node!

You never want a either to become a common!
If you bring the two together you have a short!
Which one is hot is a matter of a mental play or choice!

In AC you must use a transformer where one line is a common and the other is a neutral for single phase use.
In your country you have 240 volt single phase.
We use 120 volt single phase for safety reasons.
Back when electrification first started the materials used were cloth insulation material.
We also used knob or spools to separate them.
This thinking was Influence by telegraph thinking, that was also high voltage low current DC get the distances.
This is where Tesla/Westinghouse and Edison bumped heads! But as we know, DC is our Electronics’s!

Evolution is not so speedy at times!

I think I just hijacked this thread but that’s just between you and I.
(:-)
Sorry there BB, I GET GOING on like a switch!

Phil