Driving in theWind
by Brian Brown
Gusty wind can be one of the trickier driving situations to deal with, especially with erratic gusts that rapidly change direction and intensity. Since the driver can't see these as they come, it's only possible to react after they've already affected the car's behavior.

The main goal when driving in heavy wind is to keep the car as stable as possible (a goal in all driving situations, of course).

Strong head winds mostly just require corrective action with the gas pedal. The main thing here is to maintain a close awareness of the car's speed (listen to drivetrain pitch, feel the force of the gusts as they come, and keep the speedometer in your peripheral vision), and feed extra pulses of gas to counteract the wind gust pulses as precisely as possible. The faster you react to the gusts, the easier it is to maintain stability. It's much harder to speed back up into a head wind once the car has slowed down to any degree.

Tail winds are similar to head winds, in that they are primarily compensated for with the gas pedal. The main thing to keep in mind with these is that tail winds can significantly increase a car's stopping distance.

Cross winds are the trickiest to deal with. Any side force (wind) on the car has to be counteracted with steering if the car is to continue to go in a straight line. A lower (side) coefficient of drag helps, but with a given car, there's nothing that can be done to significantly change this.

The ti is reasonably stable when it is hit by a cross wind. Any body lean caused by the wind will actually cause the rear semi-trailing arm suspension to countersteer in a way that somewhat counteracts the wind force. The front suspension at least doesn't self-steer with lean. It is, however, still quite necessary to counteract with the steering into the wind gusts.

One factor to consider is speed. Slowing down reduces the reaction forces necessary to counteract the wind. This is especially important in cold weather where the wind could also be producing slippery spots on the road. Good judgment is needed to determine how fast is safe.

Some side gust situations *can* be predicted: driving under an overpass, passing a truck, coming past the edge of a mountain wall, etc. Use whatever you can predict to your advantage.

When you're out in the open and the wind is simply erratic, it's necessary to react to gusts as you feel them. This can be very tiring and laborious if you just try to fight with the steering wheel as you feel the car being pushed out of the lane.

One important thing is to keep your eyes focused way down the road to where you want to wind up, instead of focusing on the lane markings right in front of the car (always a good practice anyway). This provides a much more stable and relaxed reference, as well providing as much advanced notice as possible for upcoming situations.

Here's a useful trick for steering technique in strong gusting sidewinds:

Position your hands on the steering wheel at either the 10 and 2 o'clock or the 9 and 3 o'clock positions. Raise up you elbows so that your forearms are diagonal at about 45 degrees. Let the weight of your arms hang down on the steering wheel. Keep your arm muscles as relaxed as possible.

In this position, when a side wind gust pushes on the car and starts to tilt the body, the inertia from your arms will cause the steering to be directed into the wind gust. Because this is a direct mechanical response, it is faster and more accurate than waiting for the brain to detect the wind gust and react. Also, because you're not fighting the gusts with your muscles, it's a much more relaxing way to drive in this type of situation.

It's necessary to adjust the specific position and angle of your arms to get the proper reaction. Basically, the higher up you raise your elbows, the stronger the steering reaction will be. It's not too difficult to find the right position that keeps the car going where you want it. It may seem a little strange at first, but hey, it works.

While doing this, it still helps to focus your thoughts as much as possible on the road.

Stability...Stability...Stability...OM...

Brian Brown. BMWCCA #130878 '96 318tiS


http://www.318ti.org/notebook/driving_in_the_wind/
September 17, 1999