Hello again folks!

Please help me out with an answer here... When replacing a thermostat (1971 2002) does a lower rating number (such as 71 degrees vs 90 degrees) make the gauge read cooler? Or make the engine stay cooler?

My dash gauge reads clear up to the red zone even though engine does not smell, act, etc, overly hot. 320i radiator is not very old, but it was recon.

Thanks in advance!