Both my 951 and n/a have a temp sensor in the upper radiator hose which is the hottest point of the cooling system essentially. I normally see between 180-185*F running on the street with ambient around 70*F. Fans kick in around 190*F at idle and cool right down. This is using a digital gauge, not an analog so its accurate to single digits.
This was using the low temp fan switch and stock range thermostat. When i ran a stock range fan switch, i was seeing temps creep up into the 205*F range when sitting at idle and takes much longer to cool off. 212 is still fine, but in my opinion on the high end of the normal range. Double check that the gauge is working accurately, clean your grounds and also clean up the connectors on the cylinder head temp sensor. Mine were heavily corroded.. i ended up completely replacing the spade connectors which helped settle the 'bouncing' gauge. Also double check your A/C condenser and radiator fins are not clogged with road debris.
My dash gauge is usually under the 1st mark and i dont think i have ever seen it go past the 1/2 mark during normal driving, even in the dead of summer. Personally i think the dash gauge reads a little bit low. I have a theory that this is the same reason the gas gauge reads 3/4 of a tank on almost every late interior 944 i have ever seen. I think the needle slips on the peg a little bit after 20 something years causing slightly lower readings. Thats just my theory
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