The complex world of automobiles and maintenance lends itself to plenty of myths, half-truths and harebrained remedies that seem to propagate all the time. With so many theories and old sayings floating around, it's tough to separate fact from fiction.
One area that seems particularly prone to myths is that of cold weather driving. Yes, it's definitely true that weather can affect a vehicle, and temperature plays a big role in the various things that go on in the engine. However, some people overexaggerate the effects of winter on a vehicle to the point that myths have become taken as fact.
For example, many will tell you that winter is the worst time of year for batteries, and that more people encounter dead batteries in the cold weather than any other time of year. In reality, these people likely just remember the experience more than their summer battery deaths because nobody likes standing out in the cold waiting for a jump.
There are several factors from cold weather that can affect the battery. The engine is a bit more difficult to start because the oil is not as fluid, and batteries can't charge quite as much as in the summertime. While this can lead to trouble starting a car, it doesn't necessarily mean the battery is completely dead. In fact, it's more common for a battery to fail outright in the summer, when high heat can damage the part's electrolyte.
Perhaps because of these dead batteries, many drivers fear that their vehicle won't start in the winter. Those who deal with temperamental old cars might think that they have a ticking time bomb waiting in the parking lot, just waiting to ruin their day. Some drivers' solution to this is to try and start their car at various points throughout the day, with the thinking being that if it is continually able to start, it should be good for the ride home. At offices, this could mean running out to start the car every few hours.
In reality, this doesn't do all that much. There's no guarantee that starting the car at noon will ensure that it starts up at quitting time. If the car started and got you to work in the morning, it should be fine for the ride home - and if it's not, having started the car earlier in the day wouldn't have prevented anything from occurring. Those who invest time in this trick would be better served by actually investigating the problems in their car and getting it fixed then worrying about starting and restarting at all hours of the day.
Another myth that is often repeated is the old trick of driving with sandbags in the trunk. The idea is that if a driver weighs down the back of their vehicle, they'll be less prone to fishtailing and gain better traction. This is actually more of a half-truth: it's something that used to be true, but doesn't really apply anymore. The trick only really works on rear-wheel drive cars, and owners will likely only notice it on much older models with poor weight distribution. Today's rear-wheel cars have much better tires for dealing with winter weather and are also already balanced for driving in winter weather.
Using sandbags on a front-wheel drive or all-wheel drive car, which makes up the majority of vehicles on the road today, will do nothing but potentially cause you to oversteer and lose handling up front.