best way to preheating engine?
I've heard that low-speed driving is better than preheating a car from a
standstill. I heard that the reason is the amount of oxygen. Then, if you blow the
wind with a fan in front like when driving, can you see the same effect?
The reason you drive slow rather than idling the car is to save gas. The thermostat keeps the coolant from circulating through the radiator when the engine is cold.