I own the vehicle as a winter hack that I enjoy a bit of light off roading and laning in, nothing serious, but as I said I do like to learn as I go along hence the question.
Now I know so from now on in my life I can say I know how the discovery 4x4 system works.
EXACTLY!!
It's a variant of the "need to know" syndrome.
One thing you need to know is that when you DO get the Disco stuck somewhere, you are probably well and truly S-T-U-C-K !
That's not a Mini or a Honda Civic out in the mud ... it's two and a half tons of Disco sunk to the axles and floorpan!
CharlesY