During my last trip, the coolant increased to 183 within 2.5 miles, stayed below 195 for 50 miles without the fan being plugged in, on a mid 90's degree day, and my mileage was the best it has been. The OE thermostat temperature appears to be
170 degrees.
Is it true that a larger radiator doesn't affect the temperature until the thermostat opens, and doesn't keep the temp any lower before that, but simply prevents it from going higher as quickly after the thermostat opens?