Parallels Between Driving and Skiing

Snow Country
September 1994
Original draft, by Tom LaRocque

"What 60 percent of the skiers we see need to be told," Steve says, "is 'get out of the back seat.'" Most recreational skiers, fearful of falling, lean too far back, weighting the skis' tails, increasing speed, and hindering their ability to initiate turns. Phil agrees: "It's a mental thing. It's very unnatural for somebody to say, 'I'm going to hurl my body down this hill.'"

Our talk occurred last season just an hour before the third session of the Mahre Training Center, an instructional series for recreational skiers. That they spoke in metaphors rooted in cars and driving is not surprising.

After finishing one-two in the 1984 slalom in Sarajevo, Phil and Steve became race drivers. The Mahres debuted in "showroom stock" cars, then got behind the wheels of 130-mph open cockpit racers in the Sports 2000 series. In 1991, they graduated to the SCCA Trans-Am Tour, driving custom-built cars that exceed 180 m.p.h. The Mahres have proven talented drivers, but like many, have had trouble finding sponsorship dollars.

While skiing differs greatly from controlling a car, the dynamics are similar. "You don't have the luxury of a steering wheel, or pedal to slow you down," said Phil. "But the weight shifts around in similar ways," in response to acceleration, braking, and steering, he said. To improve as a driver, the Mahres advise, heed what happens on skis. Skiers, likewise, may learn about skiing as they drive to the slopes.

Weight watching

When a skier leans forward ("get out of the back seat"), he slows down. When he shifts his weight to the rear, he accelerates. Similarly, when a car slows down, either from braking or backing off the accelerator, its nose dives a bit. When it speeds up, its weight shifts to the rear and its nose angles upward.

Side-to-side weight shifts are comparable as well. "In skiing, every left-hand turn is done on the right ski. In a car, every left-hand turn is done on the right tires," said Steve. Skiers are advised to commit their weight to the outer ski. For a car to turn precisely, its suspension must be firm enough to apply much of the car's weight to the pavement, rather than absorbing it.

Key to both activities, according to Phil, is balance. "In our Training Center, on the first day, all we work on is balance. Get up on the ski, get down on it. Feel the whole ski, not just the tail or the tip." Most skiers lack not only fore-to-aft balance, but up-and-down balance as well.

While amateur skiers tend to be too timid, non-professional drivers often are too aggressive, recklessly tossing around the weight of the car, unwittingly pushing it beyond the limits of control. A good driver shifts the car's weight where it's needed, within limits, he said. "The idea is to keep all that mass moving, but never exceed the grip of the tires, or gravity."

Slow Down and Steer

In driving, the time to slow down is before a turn. "That 'loads up' the front tires and increases their grip of the road," said Steve. Pre-turn braking is something drivers often do intuitively, particularly if they can't see what lies ahead.

But if the driver continues braking after a turn has begun, he's asking the front tires to do two things at once: brake and steer. On a slick road, that may be asking too much; the tires may lose their grip. When driving on a slick road, brake or steer, but don't do both.

In skiing as well, it's often necessary to drain off some speed before changing direction. But here lies a difference with driving. Turning and braking, on skis, are not separate things. Turning, in fact, is braking, if it's in the uphill direction.

"In skiing, we don't have anything to propel us forward other than gravity. If we want to accelerate, we have to release the turn sooner and go more down the fall line. If we want to slow down, we finish the turn more and go across the hill more," said Steve.

Still, recreational skiers and everyday drivers can learn a lesson from watching race drivers: Turning too abruptly threatens control. Speed should be reduced in the initiation phase, well before the crucial "apex" of a turn (see below). The sequence of actions, said Steve, is "slow down, steer, and accelerate out."

Over or Under

While a skier who stays "in the back" seat may have trouble initiating turns, one who foregoes balance and leans too far forward may have the opposite problem: His tips grab, his tails wash out, and he turns too much. In car parlance, such a situation is called "oversteer."

A car losing its grip in a corner will either oversteer or understeer. The former condition, in extreme form, is characterized by a spin—perhaps 360 degrees or more. The latter, more familiar to most people, means the car turns too little; it tends to keep going straight when the driver tries it to turn it.

"Most production cars are pushers," said Steve. They tend to understeer, due to their intentional front-heavy design. To the average driver, understeer is less threatening than an oversteer situation, because the countermeasure is intuitive: back off the throttle, and brake. This throws the car's weight forward, loading the front wheels and hopefully restoring tire grip. Unfortunately, the slicker the road, the less effective this will be.

Correcting oversteer is counterintuitive, noted Phil. When the car turns too much, and the rear end starts "coming around," turn the wheel hard "in the direction of the skid." That is, if the rear end is swinging left, rotate the wheel left. It may also be helpful to lightly punch the accelerator, provoking a rearward weight transfer and unloading the front tires, to help get them realigned in the desired direction.

Define the Line

Any turn, on skis or in a car, follows a certain "line." Ski racers choose their lines to finish fast; everyday drivers want to avoid skidding. But the two objectives are the same, said Steve. "If you're skidding or sliding, you're not taking the fastest way around."

A slalom skier tries to arrange the innermost part of his turn, or "apex," near the gate. Usually that's one-half to two-thirds of the way through the turn. If he hits his apex too early, the skier must release the turn a bit, then turn in again. "The apex is the point where you can start to release the turn," said Phil. "In a car, it's the point where you can start to unwind the wheel."

A driver should place the apex at the innnermost part of the available road space without compromising visibility. Ideally, the apex should also concur with the "vehicle behavior point," at which the car switches from an inclination to understeer to a slight tendency to oversteer. It is then possible to accelerate out of the turn with maximum traction. With practice, any driver can learn to "feel" the vehicle behavior point in turns.

Like skiing, driving can become infinitely technical. For the average winter motorist, according to the Mahre brothers, two simple rules apply. First, slow it down. Second, smooth it out. Race drivers compare the latter to "driving with an egg under your foot," said Phil. "A good driver won't just jump off the throttle and climb all over the brakes. He comes off both real easy, and applies them that way too. Everything has to be very subtle, like the moves of a good skier."