4 Reasons Why You Need To Let Your Car Warm Up In The Winter

12 Dec 2015

Yes, we all know cars need to be warmed up before you abuse them, but why is that really? I wanted to try out this ‘advanced post editor’ so I decided to pretend I’m Engineering Explained this morning.

Alright, let’s roll.

1. Get the juices flowing

You probably all knew this one already. After your car has been standing for a while, your engine oil will settle in the bottom of the oil pan. It takes around 10 to 30 seconds to get it properly circulating again. If it’s cold, your oil will be more viscous (thick) to begin with so it might take a bit more time than that. Oil plays a crucial role in reducing metal-to-metal rubbing in your engine, so you want to make sure it’s all lubed up.

Most manufacturers recommend driving off after about 30 seconds (in a chilled out manner). This way you will hit operating temperature quicker and reduce the amount of time your engine has to spend in miserable conditions. No need to idle for 10 minutes!

2. Thermal expansion

Solids - like metal - expand as they get warmer. Engineers have to take this into consideration when designing an engine, and be clever with spacings and clearances to allow room for size changes.

E.g.: Your piston and cylinder may have different thermal expansion coefficients, meaning they’ll react differently to changes in temperature. When your engine is not at operating temperature, some bits and pieces in it are essentially the “wrong” size, causing added friction, wear and tear. Not a good time to hit VTEC.

3. The sound of cold starts

When you start your car up, the engine will deliberately run at a slightly higher RPM to warm up the catalytic converter so it becomes effective and reduces emissions ASAP. The process has a distinct sound and provides a good time to get out of the car and listen to the beautiful sound of your exhaust.

4. Your tires

Your engine is not the only thing you need to warm up before you set off on a b-road blast. Cold, hard tires have noticeably less grip so make sure you take that into consideration before you understeer into your local bus stop.

Especially in this cold weather, please wait till your car warms up and don’t drive like a lunatic straight out of the driveway. It will be really grateful for it.

Comments

I have a 1996 Toyota Corolla as my winter beater an i just trash it around because i got it for 150€ and a 24pack of beer from a friend. Warming the car up before going? Nahh just pedal to the metal, rpm’s at red but that car is bulletproof. No problems at all. Engine temps stay normal no weird noises it just works. Unlike my Mini that won’t even start if its - 30C°.

I even let my winter beater warm up. But it’s just logical. In winter you start your car, and then you clean snow of it. By the time you do that, it is will almost warm.

Is there a video of that Capri?

Also so the heater can warm up…

I totally expected another trollGabz post!

I always wait for my secondary air injection pump to stop before I drive off

If I have to leave for work i go out to my car and start it then I go back in the house and leave it running. I drink my coffee and then I go out and my car is warmed up and the windows are free.
So I leave it running for about 10min. So im fine with that. Maybe we should add that the car isnt really warmed up until the oil isnt. Water gets warm pretty fast (if you dont have a diesel. Wich i dont understand why you would) but oil takes at least 3-4 times that long. I only put my foot down after about 10-15 km mostly.

Reminds me of a little over a week ago, my chemistry teacher tried teaching everyone you don’t need to warm up the car at all. He made remarks about how “the chemical reaction of the heat and stuff in the motor is enough to warm up the motor in an instant”. I wanted to say something so bad…