Living in an area which snows every winter you grow up turning your car on and let it idle to warm up the engine, you’ve likely fallen victim to a myth that may be doing more harm than good.

The reality is 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 cold starting works

Under ideal conditions, your car engine runs on a mixture of air and vaporized fuel, gasoline in this case. When the air/fuel mixture enters a cylinder, a piston compresses it, which combusts, 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 you call running “rich” – and that’s where the problem begins.

[perfectpullquote align=”full” cite=”” link=”” color=”” class=”” size=””]The bottom line: Contrary to popular belief, idling your car does not prolong the life of your engine, rather it shortens it.[/perfectpullquote]

The engine is actually putting in extra fuel to make it burn and coat the cylinder walls. Gasoline works as a solvent so when the engine is “cold-starting” or “cold-idling” for any extended time could wash oil off the walls. Running in these conditions while idling to warm-up the engine can have a detrimental effect on the lubrication and life of things like piston rings and cylinder liners, which are critical to running the cylinders and pistons that breathe life into your engine.

Hypermiling solution

Thankfully, your car doesn’t run rich the entire winter. It only happens when the gasoline is cold. Once your engine warms up to about 40 degrees Fahrenheit, the car transfers to normal fuel consumption rates.

So you might think by idling your car, you’re warming it up, which will prevent this problem. But don’t confuse warm air coming from your car’s radiator with a warm engine. Idling is, in fact, the root of the problem.

“Idling isn’t really getting the engine up to temperature, and until that happens the little brain box on the engine is going to keep sending rich fuel mixture to the cylinders so that it can ensure that enough is evaporated for a consistent combustion event.”

[pullquote align=”full” cite=”” link=”” color=”” class=”” size=””]The fastest way to warm your engine up is to simply use it right away, aka drive immediately![/pullquote]

The fastest way to warm your engine up is to simply use it right away, aka drive immediately!

Do not sit idle for any extended period of time

Okay, now for the rest of the car, no major running component needs to warm-up in order to work. The power steering is engineered to work in sub-zero temperatures, so are the brakes. Idling your engine does not warm up these fluids to any degree, using them does. You will get the oil warmer and faster so that it’s flowing exactly the way it’s intended if you drive the car lightly after turning it on, within say 30 seconds to a minute. The power steering pump may groan a little bit but idling the car for five minutes isn’t doing a thing for the power steering fluid. Nothing. You’re not making the power steering fluid do anything because you’re not steering and moving the pump. So use it, by the time it takes you to scrape the snow and ice off of your windows, your car will be ready to go.

Easy Does It

Be gentle with the gas pedal at first. It takes time for your engine to warm up once you step on the gas – between five to fifteen minutes depending on driving conditions – and you’ll put unnecessary stress on the it if you go racing down the road immediately after turning your car on.

Moreover, because your car is going to run a bit rich before the engine reaches 40 degrees Fahrenheit, you’re going to get lower gas mileage than usual.

In fact, your car will be at least 12% less efficient at burning fuel when it’s cold, according to the Environmental Protection Agency and Energy Department. (Fuel Economy in Cold Weather)

If you put your pedal to the metal straight out of the driveway, you’re just wasting gas, MIT mechanical engineer John Heywood told Business Insider.

Birth of a Myth

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, electronic fuel injection became mainstream replacing the older less efficient carburetors and that technology is used in all 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. Hypermiling is a product of advances in our thinking to either save monies or eradicate efficiencies in our modern lives, so should our outdated views of how we take care of our cars.

Okay, you’ll be shivering the first few minutes driving while cold but you’ll be saving yourself fuel as well as a lot of time and money. And secretly you’ll be a hypermiler by default!

For more information visit this link on your fuel economy.