Quote Originally Posted by Meatball546
If an upgraded cooling system is keeping the engine below operating temperature, something is wrong- most likely the thermostat. You could have a giant radiator and giant radiator fans, but the thermostat only circulates coolant through it when the engine needs to be cooled.
The fact is, that when you have an upgraded cooling system, in cool weather, the engine can't get up to operating temp for the thermostat to work in a reasonable amount of time. If you put cardboard over half the radiator, the car will reach operating temperature faster, allowing you to have heat faster, and the car to run at it's most efficient temperature range faster as well.