I read in the Motor Oil University article on Bob the Oil Guy's websites that:
The automotive designers usually call for their engines to run at 212°F ( 100°C ) oil and water temperature with an oil thickness of 10. ... The engine is designed to run at 212°F at all external temperatures from Alaska to Florida.
I installed a 82.5°C thermostat on my 97 Mazda 323 BA 1.8L BP DOHC. The radiator was replaced by the previous owner and is not OEM. I'm using a premixed glycol-ethylene coolant rated between -10°C to 118°C which specifically says on the bottle not to add water. The service manual calls for 65% water to 35% coolant in environments over -15°C.
After all those details, here's my question:
When I hook up to the ECU, I find that most of the time the engine temperature stays between 85°C to 92°C. Rarely, when standing in traffic for a long time, the temp will get up to 97°C, at which point the ECU turns on the fan and the temp rapidly returns to the previously mentioned range.
Is this normal? If not, any idea's?
So far I haven't found anything regarding normal operating temps in the service manual, although that doesn't mean it's not there of course.