Most cars sold in the U.S. are either front- or all-wheel drive, and both can be safely operated in snowy or icy conditions when outfitted for the weather and driven with care. But what about rear-wheel drive cars and trucks, can they be driven safely in the snow?
Rear-wheel drive police cars and taxicabs have been operating safely on winter roads for decades, and before the 1970s, front- and four-wheel drive passenger vehicles were pretty rare. However, rear-wheel drive vehicles require more driving finesse when the roads get slick than front- or all-wheel drive cars, SUVs, or trucks.
“Rear-wheel drive is the worst configuration to drive in the snow, and obviously, all-wheel drive is the best,” says Todd Harris, president of the Portland, Oregon-based Pro Drive Racing School.
Why Are Rear-Wheel Drive Cars so Much More Challenging?
“The primary reason is about the weight distribution,” says Keith Willcome, a project engineer with Bridgestone Americas Tire Operations.
In most cars, the engine is in the front, and that’s where the vehicle’s overall weight is concentrated. Front-wheel drive cars take advantage of the weight directly over the drive wheels to provide more confident acceleration in slippery conditions. The front wheels are responsible for steering and also do most of a car’s braking, no matter whether the vehicle is all-, front-, or rear-wheel drive.
“If you’ve got to travel up the hill, the first cars you’re going to see stuck are the rear-wheel drive cars, next front-wheel drives, then all-wheel drives,” says Harris.
Rear-wheel drive vehicles are tougher to control when they do lose traction. When front-wheel drive vehicles experience wheel spin, they tend to understeer – you turn the wheel, but the car keeps going forward. If a rear-wheel drive car loses traction, there’s more of a propensity to oversteer (where the back end slides out to the side) or fishtail (when it sways from side to side.)
Many of the rear-wheel drive vehicles sold in the U.S. are performance models or sports cars with wide, low-profile summer tires, or pickups with little weight over the rear tires – all factors that further reduce winter driving capability.
How Can You Improve Rear-Wheel Drive Snow Performance?
“Any car can be safe to drive in the snow, if it’s properly equipped for winter conditions,” says Willcome. “Winter tires will help you to accelerate, stop, and corner much better than all-season tires.”
Many people still call them snow tires, but modern winter tires are designed to work better in more than just snowy or icy conditions. With their special rubber compounds that can stay flexible in cold weather, winter tires can also improve traction in cold, rainy conditions and on sub-freezing dry roads.
If your car has summer tires “it is absolutely necessary to equip your car with winter tires before attempting to drive in the snow,” says Willcome.
Even if you get a car with summer tires moving in snow or ice, you likely won’t be able to stop or steer. Winter tires should be installed in sets of four, and never just on the front wheels, according to Willcome.
Weight can be put in the back of pickups to provide additional traction, but it must be secured so that it doesn’t move when you brake hard, corner, or get in a collision. The added weight can also increase stopping distance, so you’ll need to find the right balance of benefit vs. handicap and place any weight directly over the drive axle.
Electronics are also helping improve drivers’ ability to control their rear-wheel drive cars in snowy conditions. All cars sold today feature traction control and vehicle stability control. Traction control senses when a wheel is losing traction and applies the brakes or reduces power to keep it from spinning. Vehicle stability control uses various sensors to determine if a vehicle is traveling in the direction that you want it to go. It then applies the brakes on one or more wheels to bring the car back to the desired direction of travel.
Some vehicles also have a snow mode for the transmission. By starting the car rolling in second or third gear, wheel slip can be reduced or prevented.
All-wheel drive is becoming an option on traditional rear-wheel drive sporty cars. Dodge recently announced an all-wheel drive version of the Challenger. Mercedes and BMW have joined Audi in producing an array of all-wheel drive sports sedans. An all-wheel drive 2017 Mercedes-Benz E-Class sedan carries a $2,500 price premium over a rear-wheel drive model.
Practice Makes Perfect
“The only way you get better at anything is by practice,” says Harris. “We teach car control year-around. By putting in a little bit of time, you understand what makes a car skid, and you learn how to keep your car from skidding.”
Harris’ school teaches drivers car control techniques using specially equipped vehicles that can simulate skids in any weather. Other driving schools use low-friction surfaces covered with water to simulate winter driving conditions. Bridgestone offers a class in Steamboat Springs, Colorado where you can perfect your winter driving skills on snow and ice driving courses.
Regardless of what type of car that you are driving, Harris cautions against getting overconfident in the winter prowess of your vehicle or your driving skills. “There’s a lot of all-wheel drive out there,” he says, “and people can overestimate their driving ability or the capability of their vehicles.”