I will one last time try to explain it:
Our goal is to maintain a certain speed with the least possible use of Hp / Kwh / fuel. Right ?
The ECU constantly reads engine temp, air temp / mass, throttel position / vaccum, and oxygen level in the mix.
Now - let say, that you for going 50 mph have to take the throttle to position 20 out of for instance 60...
Now you lower the air intake temp with 40 degrees centigrade, thus adding 8 - 12% more oxygen to the mix.
What will happen?
Will the car accelerate? Decellerate? Maintain speed?
The car will accelerate, because the oxygen sensor reads a higher level of oxygen, it will add some more fuel and the car will accelerate.
To maintain speed you let go a bit on the accelerator....
What we in essence have achived with the higher level of oxygen in the colder intake air, is an improvement in engine effensicy, so that it now develops some extra kw at the wheels at a given rpm. This could also have been done by using a more energy rich fuel, but that costs....
If you don't belive me, try to add some NOX instead of the extra oxygen. You will soon be caught for speeding....
Essentially what we talk about is that the car has to over come a certain resistance to get to a certain speed.
If you lower drag you can go at the same speed with less throttle, if you lower rolling resistance in tires you can go at the same speed with less throttle, and if make the engine more effecient you can maintain same speed with less fuel.
Now there are some traps in this, as the oxygen sensor and ECU will try to adapt the mix to optimise the - for emmisions - best working temp for the catalyst converter - thus to some degree changing the above.
OK - if I'm wrong - pls tell me why - not just that I'm.