The majority of my vintage machines require the presser foot to be in the 'down' position before adjusting because the tension disc are pressed up against each other when the pressure foot is down providing for ture tension. The dial is 'not' the indicator. Less attention is paid to the number adjustment as they can be off easily. On some of my newer machines it is in the up position especially if the machine has an 'auto tension'.

I really wonder if the newer machine manuals just forgot about this issue. I'm using a Babylock Jane which is mechanical and leaving the foot down to adjust now. Not a word in their manual about keeping the foot down. The other machine I use is a computerized Brother. I'm going to give them a call and see what they say about the up/down issue because there's nothing in the manual.

You change the tension setting with the presser foot up, then you put fabric under the foot and test what you did.