4WD is good for so much more than just accelerating and cornering.
There's no other way to put it: if you live in one of the country's snowier regions, winter tires are the best investment you can make to ensure your safety on the road. Even more so than an all-wheel drive vehicle and yes, that goes for times when it's just plain cold outside and not even snowing. On the other hand, that doesn't mean that all-wheel drive and two-wheel drive vehicles are evenly matched once both have a set of winter shoes and are put in extreme conditions.
It's safe to assume that accelerating and cornering in the slush is more confidence-inspiring when power is going to all four wheels, but would you guess that braking performance is also enhanced with a four-wheel drive system? It's okay, most people wouldn't either.
That's why the Team O'Neil Rally School is here to show us the difference. For the purpose of this test, Team O'Neil uses a Ford F-350 with a snow plow attached to the front to add weight for maximum momentum. In total, Team O'Neil conducts four separate tests, two with rear-wheel drive—once with ABS and traction control on and again with it off (since we know ABS actually hurts braking performance in the snow)—and two with four-wheel drive on—again with ABS and traction control either on or off. When slamming on the brakes using four-wheel drive, it seems that the truck slows down in considerably less distance. Why is this?
That's not made clear in the video, but one hypothesis posted in the comments section postulates that it's because a four-wheel drive system makes it so all four wheels are mechanically locked so that they turn at the same rate. That means if the front tires lock up under braking, then the rear wheels also stop rolling and bring the behemoth to a stop more quickly than if the rear tires were detached from the front end and allowed to keep spinning with the fronts locked up. We'd test it ourselves, but the snow has yet to pay us a visit…