What’s the Difference Between All-Wheel Drive and Four-Wheel Drive?

iStock/PeopleImages
iStock/PeopleImages

As the weather turns nasty, you may start to think more about your car’s transmission—particularly, its ability to get you up and down muddy, snowy, or icy roads. While you may know that two-wheel drive isn’t the best option for driving in harsh weather, other terms are more confusing. Like, for instance, all-wheel drive versus four-wheel drive. Don’t all cars have four wheels (at least when it comes to sedans, SUVs, and other consumer vehicles)? As Jalopnik explains, the difference between all-wheel drive (AWD) and four-wheel drive (4WD) is more than just semantics—and which type you need depends heavily on the kind of driving you do on a regular basis.

When a car manufacturer specifies something as two-, four-, or all-wheel drive, the company is referring to the tires that receive power from the engine. With two-wheel drive, the engine powers either the front axle or the back axle of the car, meaning that the engine is moving only the front tires or the back tires. The other axle is just rolling along. When four-wheel drive (sometimes referred to as 4x4) is engaged, meanwhile, the engine rotates all four wheels. This helps give the car extra traction on slippery surfaces like sand, ice, and gravel—so that even if one set of wheels can’t get traction on a slippery surface, the other wheels might be able to.

The key word there is “engaged.” Traditionally, four-wheel drive means that your car can drive with all four wheels, but you have to manually choose that option. The rest of the time, you’re in two-wheel drive mode. As Ray Magliozzi of NPR’s "Car Talk" once explained to a listener, four-wheel drive is “designed to be engaged when you're already stuck, or in a specific situation where you know you might get stuck—like in snow, sand, or mud. It’s not designed for normal road use, and must be disengaged before you drive on dry, paved roads.”

In all-wheel drive, meanwhile, the car figures out what kind of traction you need all on its own. It has sensors that figure out how much power should go to each wheel to give you the best traction without any input on your part. This is a useful feature for driving in a variety of different conditions, while a dedicated four-wheel drive mode might be better for serious off-roading.

Be warned: There are downsides to all that extra traction. A car’s engine has to work harder to power all four wheels. Those engines are also heavier, which itself takes more power to move. As a result, four-wheel or all-wheel drive cars usually use significantly more fuel than your typical two-wheel drive model.

There are other caveats to this explanation: Full-time four-wheel drive cars do exist, but they differ slightly from all-wheel drive vehicles because of how the two axles of the car move in relation to each other. In four-wheel drive, the front and rear wheels are locked together so they spin at the same rate; in all-wheel drive, the wheels aren’t locked like this—different amounts of power go to the different wheels as needed.

All this said, even if you live somewhere with snowy winters, it doesn’t necessarily mean you should spring for all-wheel drive. If you’re driving a lot in inclement weather—say, if you live in South Dakota or Wyoming rather than sunny Southern California—winter tires may actually be a lot more important than which wheels the engine is powering. Need proof? Watch the video comparison here.

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Why Are There 10 Hot Dogs to a Pack But Only 8 Buns?

tacar/iStock via Getty Images
tacar/iStock via Getty Images

Watching competitive eating champion Joey Chestnut cram dozens of hot dogs down his throat would make anyone crave a grilled log of processed meat this summer. But shopping for hot dogs can be a confusing experience. The dogs are typically sold in packs of 10, but the buns are sold in packs of eight. What's behind this strange dog and bun inequality?

According to the National Hot Dog and Sausage Council—yes, there is a National Hot Dog and Sausage Council—there’s a good reason for the discrepancy. For starters, distributors of hot dogs are almost always different from manufacturers of baked goods like rolls. The hot dogs are sold in packs of 10 because producers of meat (or meat-like) products selected that quantity when hot dogs started to sell at retail grocery stores in the 1940s. Oscar Mayer, which led the charge into direct-to-consumer hot dog packaging, sold hot dogs by the pound in accordance with how meat is typically priced. Having 10 dogs that weighed 1.6 ounces each seemed like the ideal distribution of weight.

Bakeries, meanwhile, have standards of their own. Buns and sandwich rolls are usually sold eight to a pack because the baking trays for the elongated buns are typically sized to fit that number. Two sets of four buns come off the tray, which is the reason why buns are often still attached to one another when you open a bag.

These standards were created independently of one another: Bakeries weren’t too preoccupied with hot dogs when they were settling on a four-roll tray standard, and hot dog manufacturers weren’t thinking about how difficult it would be for bakeries to break from their conveyor system to offer 10 buns to a pack.

It can be frustrating if you buy just one or two packages of each, but if you’re hosting a big enough party, the uneven number doesn’t matter. You just need to buy five packages of buns and four packages of hot dogs to have 40 matching pairs. No complicated calculations required.

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When Are the Dog Days of Summer?

Dorottya_Mathe/iStock via Getty Images
Dorottya_Mathe/iStock via Getty Images

The official “dog days” of summer begin on July 3 and end on August 11. So how did this time frame earn its canine nickname? It turns out the phrase has nothing to do with the poor pooches who are forever seeking shade in the July heat, and everything to do with the nighttime sky.

Sirius, the Dog Star, is the brightest star in the sky. The ancient Greeks noticed that in the summer months, Sirius rose and set with the Sun, and they theorized that it was the bright, glowing Dog Star that was adding extra heat to the Earth in July and August.

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