Why I installed a low temp thermostat.

[Jaak]

It seems the T-stat opens earlier to get the coolant flowing earlier, that's all it does.

Nothing else changes with the temp as the car still generates the same amount of heat as before. The temp gague is slow to change unlike the ones the 944's have and show's an average over a short time span. My old 951 used to move up and down all the time ...

[Meir]

The key to the question has to do with the somewhat strange cooling system in these engines. I'm sure someone can explain it better then me, but as far as I understand, the temp sensor is located at the return from the rediators (I think you can fined the full explanation in earlier posts in this tread). There are parts of the engine (around cylinder 6 if I remember correctly) that are much hotter than what you see on the gage. So even thogh the gage show same readings, the engine itself runs much cooler.
That's more or less what I understood before I got main