What the Heck?! Thread (Closed)

[siegecrossbow]

Don't know whether this is the right place to post this, but want the word out nonetheless.

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Harsh driving conditions in winter are already hard on your car, but you could be making things a lot worse if you're turning your vehicle on in the morning so it can 'warm up' before you drive off.

If you're one of the many drivers who thinks it's important to idle your car — turn it on and let it sit — in these frigid winter months to protect the engine, you've likely fallen victim to a myth that may be doing more harm than good.

We spoke with mechanical engineer and former drag-racer

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about the pervasive myth that you need to warm up your car in the winter.

For the last 26 years, Ciatti has worked on combustion engines — engines that generate power from burning fuel, like gasoline — and currently oversees all of the combustion engine work at

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in Illinois.

To get straight to the point, Ciatti said that idling your car in the cold not only wastes fuel, but it's also stripping oil from critical components that help your engine run, namely the cylinders and pistons.

How it works
Under normal conditions, your car engine runs on a mixture of air and vaporized fuel, gasoline in this case. When that mixture enters a cylinder, a piston compresses it, which — at the risk of oversimplifying — generates a combustion event, powering the engine.

But when it's cold outside, gasoline is less likely to evaporate. Your car compensates for this initially by adding more gasoline to the air-vapor mixture — what Ciatti calls running "rich" — and that's where the problem begins. Here's an animation that shows how pistons drive the cylinders in your car to generate a combustion event:

If you put your pedal to the metal straight out of the driveway, you're just wasting gas, MIT mechanical engineer

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told Business Insider.

"[Idling] does of course use fuel, and the bigger the engine, the more fuel," he said.

Roots of the myth

(RM Sotheby's)
Some myths die hard, and the notion that you need to idle your car in the cold is no exception. The basis for this thinking extends to an age when car engines relied on carburetors.

Before 1980, carburetors were the heart that kept car engines pumping.

From the 1980s onward, however, electronic fuel injection took over and is still what powers today's car engines.

The key difference is that electronic fuel injection comes with a sensor that feeds the cylinders the right air-fuel mixture to generate a combustion event. Carburetor-run cars lacked this important sensor.

Therefore, if your gasoline was too cold, your car wouldn't run rich, it would simply stall out. In those days, it was important to get the carburetor warm before driving. But those frustrating times met their end long ago, and so too should pointless idling.

Yes, you're going to be cold during the first few minutes it takes your radiator to warm up and start blowing air that feels comfortable. But you'll be saving yourself fuel as well as a lot of time and money.

 

[delft]

An anecdote in yesterday's paper tells how a man boosts to his wife, the wife is telling the story, that using his newest app he turns on heating in his car from in his bed so that a short while later he can drive his electric car away in all comfort. But when he gets outside the woman living next door drives away in her old fashioned car with infernal combustion engine while the plug on the cable that fed his car through the night is frozen fast in its socket.

 

[solarz]

An anecdote in yesterday's paper tells how a man boosts to his wife, the wife is telling the story, that using his newest app he turns on heating in his car from in his bed so that a short while later he can drive his electric car away in all comfort. But when he gets outside the woman living next door drives away in her old fashioned car with infernal combustion engine while the plug on the cable that fed his car through the night is frozen fast in its socket.

Electric cars are just not suitable for cold countries, as battery life drastically shortens in cold weather.

 

[Jeff Head]

Don't know whether this is the right place to post this, but want the word out nonetheless.

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Well, I think that if one is wise in their use of the care (ie. do not race off after just entering the car, whether you let it warm up or n9ot), then idling is not such a bad thing.

Most people I nknow who do so are not trying to help their engine as much as they simply want the car to be wrm when they get in and drive away.

when it is 10 below zero and you get in your car...if you do not let it warm up, it may take quite some time for the engine to warm up enough to blow hot air out the heater and/or defrost.

but if you let it idle for 5 minutes before going out, then you get into a car whose heater and defrost keep you much warmer, much sooner.

That's why most people around here let their combustion engine vehicles warm up. They would rather use a little more gas and be warmer, than to drive cold. And on days when there is ice fog, or conditions requiring a good defrost...it is also safer.

 

[siegecrossbow]

Well, I think that if one is wise in their use of the care (ie. do not race off after just entering the car, whether you let it warm up or n9ot), then idling is not such a bad thing.

Most people I nknow who do so are not trying to help their engine as much as they simply want the car to be wrm when they get in and drive away.

when it is 10 below zero and you get in your car...if you do not let it warm up, it may take quite some time for the engine to warm up enough to blow hot air out the heater and/or defrost.

but if you let it idle for 5 minutes before going out, then you get into a car whose heater and defrost keep you much warmer, much sooner.

That's why most people around here let their combustion engine vehicles warm up. They would rather use a little more gas and be warmer, than to drive cold. And on days when there is ice fog, or conditions requiring a good defrost...it is also safer.

That's very true. In Texas we normally don't have this issue .

 

[B.I.B.]

Idling ones car before driving off to improve engine wear and putting the gear into neutral(manual gear change) when waiting at lights (to prevent riding the clutch) was part of the driver care/skills taught when learning to drive.

 

[plawolf]

Well, I think that if one is wise in their use of the care (ie. do not race off after just entering the car, whether you let it warm up or n9ot), then idling is not such a bad thing.

Most people I nknow who do so are not trying to help their engine as much as they simply want the car to be wrm when they get in and drive away.

when it is 10 below zero and you get in your car...if you do not let it warm up, it may take quite some time for the engine to warm up enough to blow hot air out the heater and/or defrost.

but if you let it idle for 5 minutes before going out, then you get into a car whose heater and defrost keep you much warmer, much sooner.

That's why most people around here let their combustion engine vehicles warm up. They would rather use a little more gas and be warmer, than to drive cold. And on days when there is ice fog, or conditions requiring a good defrost...it is also safer.

I always let the car idle a bit in cold weather mostly to help visibility.

In my experience, if you jump straight in and drive off, there is a risk of your windows fogging up as the heating kicks in, which can be dangerous.

I always run the heater and window fans for a bit before driving to make sure that doesn't happen during cold spells by making sure the windows are properly warmed up before leaving the drive.

 

[delft]

Well, I think that if one is wise in their use of the care (ie. do not race off after just entering the car, whether you let it warm up or n9ot), then idling is not such a bad thing.

Most people I nknow who do so are not trying to help their engine as much as they simply want the car to be wrm when they get in and drive away.

when it is 10 below zero and you get in your car...if you do not let it warm up, it may take quite some time for the engine to warm up enough to blow hot air out the heater and/or defrost.

but if you let it idle for 5 minutes before going out, then you get into a car whose heater and defrost keep you much warmer, much sooner.

That's why most people around here let their combustion engine vehicles warm up. They would rather use a little more gas and be warmer, than to drive cold. And on days when there is ice fog, or conditions requiring a good defrost...it is also safer.

I remember reading some thirty or forty years ago an article by a Montana postman, making rounds of four or five days every week, that said he preferred driving without using the car heater, just being well clothed, because he reasoned that when driving like his younger colleagues comfortably in a well heated car and meeting with trouble he might be dead before he could put on sufficient clothes.

 

[Air Force Brat]

Don't know whether this is the right place to post this, but want the word out nonetheless.

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Another non-sense article from some-one who has never turned a wrench, and a racing engineer who doesn't have to live in the real world. It is always beneficial to pump several time in a carbureted engine to preload a rich mixture, before turning the key, and a minute to 5 for an engine to get up to operating temperature before accelerating beyond idle, allowing the oil to warm enough to circulate to each of the many crank, rod, cam bearings etc., before putting a "load" on them by accelerating.

A fuel injected engine that maintains the fuel pressure at an operating level, likely does not need to be "primed", and can be started by simply turning the key? If it doesn't there is likely a leaky o ring or two, and you may indeed have to pump the accelerator to enrichen your mixture to get a light on a kold morning. Recip aircraft have a small plunger, which injects raw fuel into the engine in order to get it to hit! you increase the number of pumps as the temp goes down.

As someone who operates a fleet vehicle, they are all diesels, they all have block heaters, and we preheat for 5 to 15 minutes in order to get them up to an "operable" temperature. You will note that many diesel vehicles have a canvas cover or "bra" over the radiator in order to keep/maintain that vehicle at an efficient operating temperature.

 

[Jeff Head]

I remember reading some thirty or forty years ago an article by a Montana postman, making rounds of four or five days every week, that said he preferred driving without using the car heater, just being well clothed, because he reasoned that when driving like his younger colleagues comfortably in a well heated car and meeting with trouble he might be dead before he could put on sufficient clothes.

I lived in Montana for several years.

In the winter it is very cold there.

But anyone who would go out in their auto, the winter there, heater or no heater, without sufficient emergency clothes is foolish and a horrible accident and tragedy waiting to happen.

One thing that is drilled into anyone is to take along plenty of arctic style clothing and supplies for emergencies.

Cars break down and have trouble, whether a postman or not.

I cannot imagine anyone, in the middle of winter there...not using their heater. When it is 25-30 below zero Fahrenheit, inside a vehicle with no heat it is going to get very, very cold.