Drive gently for best way to warm up engine, car

Patience provides heat when it’s time

DEAR CAR TALK: I have a car-related question that’s been bothering me for a while. I was born and raised in a place where heat was far more of an issue than cold, so I grew up learning that at high temperatures, using the heater for the passenger compartment could be used to cool the engine if it started heating up too much. Now that I’ve moved to a place where it snows, I’m being told that when it’s cold, using the heater actually will warm the car faster, because the thermostat will request more heat from the engine, causing it to come up to temperature faster. True? Thanks! — Patrick False. You’re welcome. The first part is true. The heater is, essentially, a smaller radiator behind your dashboard. And when you turn it on, you draw heat away from the engine and into the passenger compartment.

If the engine is starting to overheat, adding even a small extra radiator will help cool the engine — even if it ends up melting your Crocs.

But drawing heat away from the engine won’t make it warm up any faster. There’s no “switch” or “thermostat afterburner” setting that commands the engine to warm up faster if you ask for heat. It’s always warming up as quickly as it can.

So if your goal is to get heat as quickly as possible, your best bet would be to start the engine and, with the heat off, drive away immediately (driving warms up the engine faster than idling). And then check after a couple of minutes. When the air coming out of the vents is no longer colder than the air in the car, leave the heat on. Or, if you have a temperature gauge on your dash, just turn on the heat as soon as the temperature needle moves at all.

Cars with automatic climate control do this for you automatically. They’ll let the engine start to warm up and wait until there is heat before they start blowing air.

Now, once you turn on the heat, you’ll cause the engine to take a little longer to get to its full operating temperature where it runs at its most efficient, but you won’t harm your engine by delaying its warmup a little bit — especially if you’re driving it gently.

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