Why You Shouldn’t 'Heat Up' Your Car's Engine In Cold Weather

iStock/borchee
iStock/borchee

When the inside of your car is no warmer than the frozen tundra outside, it’s easy to believe you need to let your engine “heat up” for a minute or two by idling in your driveway before driving away. The old adage goes that giving your engine time to reach its normal operating temperature is easier on your car than hitting the gas as soon as you turn the ignition on. One 2009 study showed that, on average, Americans believed a car's engine should be left to idle for nearly four minutes in subfreezing temperatures—but it turns out this behavior is not only bad for your wallet and the environment, but your car as well.

In 2016, Business Insider spoke with former drag racer Stephen Ciatti to get to the bottom of this widespread myth. Ciatti has a PhD in mechanical engineering from the University of Wisconsin-Madison and has worked on combustion engines for nearly 30 years, so he knows a thing or two about how to best treat your car. And he says that idling your machine in the cold only leads to a shorter lifespan for your engine.

In older car models that relied on carburetors to run, frigid weather did pose a threat to engine performance. Gasoline is less likely to evaporate in colder temperatures, which would have led to carburetors failing to get the right mixture of air and fuel into the engine. This sometimes caused cars to stall out, and that's likely what led to the practice of heating up our vehicles in our driveways in the winter. But if you’re driving a car that was made in the past few decades, this is no longer something to stress over. Beginning in the 1980s, car companies began replacing carburetors with electronic fuel injection, which uses sensors to calculate the correct mixture of air and fuel to supply your engine with.

When temperatures dip below freezing, your engine is already aware of this and adjusts by introducing more gasoline into the fuel mix. By letting your car idle, you’re subjecting your engine to more gasoline-rich fuel than necessary, and this ends up stripping oil from your engine’s vital components.

"Gasoline is an outstanding solvent and it can actually wash oil off the [combustion chamber's] walls if you run it in those cold idle conditions for an extended period of time," Ciatti told Business Insider. He said this washing action can gradually "have a detrimental effect on the lubrication and life of things like piston rings and cylinder liners." So in the end, what you intend as gentle behavior toward your car’s engine could turn out to be the opposite.

Once your engine reaches a temperature of around 40 degrees it switches back to its regular fuel mixture, but idling doesn’t help it hit that point any faster. According to Ciatti, the fastest way to heat up an engine is to actually drive. But don’t take that as an excuse to go gunning down the driveway: Your engine will take between five and 15 minutes to reach a normal temperature from the moment you hit the gas. Until then, go easy on the pedal to avoid putting additional stress on your engine.

This article originally appeared in 2016.

The Reason Dogs Twitch in Their Sleep

Tetiana Garkusha/iStock via Getty Images
Tetiana Garkusha/iStock via Getty Images

The sight of a dog batting its tiny paws around while sleeping is irrefutably adorable, and it’s not hard to imagine that your beloved pet is dreaming of swimming, fetching a Frisbee, or bounding around the yard in pursuit of a scampering squirrel.

In truth, that’s pretty much exactly what’s going on. Dogs, like humans, dream during the REM cycle of sleep, and their twitches are responses to whatever’s happening in those dreams. Though all dogs can exhibit muscle movements while dreaming, PetMD reports that it most often affects younger and older dogs. This is because of the pons, a part of the brainstem with two “off” switches that regulate movement during the sleep cycle.

“If either or both of these ‘off’ switches is not fully developed or has grown weak due to the aging process, then the muscles are not completely turned off and during dreaming, the animal will start to move,” Stanley Coren, a neuropsychological researcher and former psychology professor at the University of British Columbia, told PetMD. “How much movement occurs depends upon how effective or ineffective these ‘off’ switches are.”

As long as your dog looks like it’s having a grand old time in its dreams, you can sit back and enjoy the show. If you think your dog might be having a nightmare, be careful about waking it up. As the American Kennel Club (AKC) explains, a dog woken abruptly from a bad dream might bite you before it realizes its distress wasn’t real.

You should, however, learn to recognize the difference between a normal dream and a seizure.

“Some [dogs] manifest dreaming with twitching, paddling, or kicks of the legs. These movements are often brief (less than 30 seconds) and intermittent,” Jerry Klein, the AKC’s chief veterinary officer, described on the AKC website. “Seizing dogs’ limbs, on the other hand, tend to be rigid and stiffer, with more violent movement.”

The seizure can also be accompanied by loss of bowel control. If that description sounds familiar, you should talk to your veterinarian.

[h/t PetMD]

The Reason Doctors Have Such Sloppy Handwriting

Rostislav_Sedlacek/iStock via Getty Images
Rostislav_Sedlacek/iStock via Getty Images

It seems counterintuitive that doctors—widely regarded as some of the smartest, most detail-oriented people out there—so often have horrible handwriting. From a patient’s standpoint, it could seem downright terrifying. If your pharmacist misinterprets your trusted physician’s chicken scratch, you could wind up with a dangerously high dosage of medicine, or even the wrong medicine altogether.

In 2006, the National Academies of Science's Institute of Medicine estimated that doctors’ sloppy handwriting was killing more than 7000 people per year, and preventable medication errors were harming around 1.5 million Americans annually. Many medical offices have since switched to electronic medical records and prescriptions, and some states have even required them to do so.

But that doesn’t tell us why doctors’ penmanship is so poor in the first place. One reason is because doctors have to write much more than we realize.

“In the medical field, if it’s not documented, it didn’t happen,” Celine Thum, medical director at ParaDocs Worldwide, told The Healthy.

If you’re the very first patient of the day, the record of your visit and any prescription slips you get might be perfectly legible. Ten hours and dozens of appointments later, however, your doctor’s hand muscles are probably pretty cramped.

The content they’re writing isn’t particularly easy to spell, either. If a doctor is jotting down glomerulonephritis, for example, they may not stop to make sure all those vowels are in the right places.

“We have so many technical terms that are impossible to write,” Thum said. “You sometimes scribble to cover the error.”

However, if a prescription looks indecipherable to you, it’s possible that your doctor is using shorthand that your pharmacist will immediately understand—like the abbreviation QD, from the Latin phrase for “one a day.”

If you’re confused about what the doctor has written on your prescription slip, you can always ask them to clarify aloud, and double-check that it matches what’s printed on your prescription bottle.

[h/t MSN]

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