As the temperatures drop and the snow flies in the Northern chunk of the U.S., there’s a lot of advice that goes around regarding driving in inclement winter weather. Some of it is legitimately good advice, and some of it is old wives’ tales — some of which have more merit than others. There’s one winter driving myth, however, that trumps all others in stupidity. Not only is it ineffective in giving you a better winter driving experience, but it can actually make it worse.
I first heard it a couple winters ago when I was working as a mailman. During a particularly cold morning, I overheard advice being exchanged in the post office as we prepared to brave the elements and bring the all-important mail to our customers. The advice was this: one of my fellow mail carriers advised another to turn on the headlights of the Grumman LLV mail truck and leave them on for a couple minutes before attempting to start it. The idea is that turning on your headlights gets the juices flowing in the battery of the truck and will give you a better chance at a successful start on the first attempt.
This is ludicrous advice and you should never, ever do this.
Let me explain how car batteries work. They’re charged while the engine is running, from the alternator, and that’s what makes them last so much longer than the AA batteries in your Game Boy Color. When the engine is running, the battery is charging — and a decent battery will last you at least a few years before it just can’t hold a charge anymore.
After you’re done with your car or truck for the day, the battery sits there, not being charged by the engine. When you first go to start it in the morning, the battery’s charge is at its lowest, because it just went several hours without any love from the alternator. That’s why, when you have trouble starting your car, it’s usually after it’s been sitting without the engine running for an extended period of time.
So, now that you know how car batteries work, which you probably already knew, do I even need to explain why it’s a terrible idea to turn on your headlights before trying to start your car or mail truck in the morning? Why on earth would you want to start draining your battery of juice without the alternator running? Did someone come up with this advice as a prank? Turning on your headlights does not "wake up your battery in the morning," informing it that you’d like it to start the engine soon, please. It just drains it, worsening your chances of a successful start. Clearly, the person giving this advice has never had a project car with a battery that had to be coddled with every measure taken to not drain the thing as to get as many cranks out of it as possible without having to hook up a charger or give it a jump start.
I thought this idea was so crazy that I did some research online to find out if this was common advice or just limited to this one woefully misinformed mail carrier. It turns out it’s a somewhat common practice and people have been doing this for years.
Since you’re reading Oversteer and since you probably know a thing or two about cars, informing you of how bad of an idea this is isn’t necessarily for you — but, rather, for the non-car people in your life. If you know anybody who does this, tell them to kick that ridiculous habit this winter if you care about them. If you don’t care about them, then tell them what a great idea it is to turn on your headlights before trying to start your car on cold mornings.