No it just quoted the spread. I found it on another forum about 3 years ago. If you want to be really sure then you need to fit something like a SCANGAUGE II that will give you exact real time temp readings. (I must post a pic of my Scangauge mounted.)
I would not trust the BMW "Idiot" gauge for anything. Older models (70's & 80's)had a real gauge that would vary quite a lot with driving/outside temps etc. I guess they got sick of answering questions and doing free warranty cooling system checks when owners saw the gauge reading higher temps.