The wind chill factor: not just for humans.

Dear Car Talk

Dear Car Talk | May 01, 1995

Dear Tom and Ray:

I have a friend with a 1990 Honda Prelude. This past winter on the coldest night of the year, she forgot to put her car in the garage. They were also predicting extremely low wind chill temperatures. I told her the wind chill doesn't effect cars, only living flesh, so she didn't need to go out and move the car into the garage. Needless to say, she left her car out and it wouldn't start in the morning. She got towed, and I got the cold shoulder for a while. My question is; does the wind chill affect the ability of the car to start, or just low temperature?

RAY: The "wind chill factor" describes how cold the outside temperature FEELS when the wind speed is factored in. But since engines don't "feel" anything, the wind chill factor doesn't apply to engines. So you're right, Dave.

TOM: Wind can have an effect on how quickly the engine cools, but even that wouldn't make any difference by the next morning.

RAY: When you park your car outside on a cold, winter night, the temperature of the engine (a couple of hundred degrees) and the temperature of the air (a couple of degrees) eventually equalize. If there's wind, and the wind blows more cold air across the engine, the temperatures will equalize more quickly. So with a strong wind, your engine might be at ambient temperature (a couple of degrees) at 9PM instead of 10PM. Big deal, right?

TOM: So it makes no difference the next morning when you come out to start the car. And wind chill will never make the temperature of the engine any colder than the outside temperature. That's impossible.

RAY: It sounds like the only thing that got colder due to the wind chill factor in this case was your relationship, Dave. Good luck warming it up.

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