What does the temp gauge represent?

Borrow your wife's meat thermometer and open cap (when cold) and stick it in and start car. As temp on gauge rises compare to thermometer and you'll know what your gauge reads on your car. Did this with mine and found that your #3 pic was 185 on my car. No more worries.

I'm going to try this. So far I have been trying ot find where she keeps it. I do not want to ask her for it, because she'll ask what I am going to do with it, and I don't want to answer that question.