The Line in Winter: Cold-Weather Driving Tips

On snow and ice, the margin is small between "frick that was close" and a tree-thumping mistake. Even the most well-prepared and cautious drivers can find themselves in deep yogurt. What follow are some tips on avoiding winter disasters, as well as advanced driving techniques that can help you stay out (or dig out) of trouble.

The easiest, cheapest way to improve your car's snow performance is to fit your vehicle with top-quality tires.

• OK may be good enough. Most U.S. drivers will survive winter just fine on first-rate all-season tires…if their rubber is almost new and the manufacturer boasts of that model's winter performance. (Check the tire company Web site.) "All-season" means the tire gives up wet and dry performance to get enhanced cold-weather mobility. It does not mean it's good in snow, just that it's better than a similar summer tire. If you live where snowplows are as common as school buses, go with four snow tires.
  
  
• Look for the snowflake. If snow traction is critical, make sure your tires have the "snowflake-on-the-mountain" symbol on the sidewall. This indicates the tire exceeds the snow grip of an industry-standard reference tire during a wheel spin test.
  
  
• Deep tread will keep you out of deep stuff. Worn-out snow tires don't match the grip of new all-season tires. Half-worn all-season tires are essentially a request to get stuck. If snow performance is important, make sure your tires — all-season or snow — have at least 6/32-inch of tread depth. New car tires start with about 10/32-inch. To measure, place a penny with the Lincoln Memorial upside down into the shallowest groove. If the roof of the inverted monument is visible, buy new tires or head south.
  
  
• Snow tires trump 4WD, AWD, traction control and stability control. A front-drive economy sedan on four top-quality snow tires will go more places than the best 4WD vehicle on all-season tires. An AWD- and stability control-equipped sport sedan on high-performance summer tires will get stuck on a snow cone spilled on an August highway. AWD and computer driver assists can only manage available traction, they can't increase grip.
  
  
• Four or none. Fitting two snow tires is false economy. Regardless of the weather — snow, rain or sun — your car will handle strangely and, likely, dangerously. The axle fitted with snow tires will have too much grip when it's snowy and too little grip when it's not. Snow tires only on the front can make you spin out on snowy turns.
  
  
• Pressure! Make sure your tire pressure is at least what the vehicle manufacturer recommends. Every 10-degree drop in ambient temperature results in a one-psi reduction in tire pressure. If you set your pressures in November, they'll be too low in February.

After tires, the next most important factor is visibility.

• Make sure you can see. If you can't see, all the driving skill in the world is useless. Clear the gunk off the inside of your windshield. When windows begin to fog, engage the air conditioner and set the system on fresh, not recirculation: Some cars do both automatically when you select the defroster. Employ high-quality windshield washer fluid with an adequately low freeze point. Replace wipers every six months.
  
  
• Clear! Remove snow from in front of headlights and taillights and regularly clean road grime from the lenses. Brush snow from the hood and roof before you start out so it doesn't blow up or slide down onto your windshield.
  
  
• Headlights on. Any time visibility is low, turn on your headlights. This is more so you can be seen, not so that you can see.

Now it's time to hit the icy roads. Here are some more tips.

• Pay attention to the road surface. If it looks slippery, it probably is. Drivers underestimate available grip on dry and wet roads, but overestimate traction in snow and ice.
  
  
• Know that traction varies. Road conditions will change from simply slushy to glare ice to just damp. A heavily traveled interstate may have plenty of grip, while its little used off-ramp is a skating rink. One place for ice to build up is where drivers brake or accelerate. Wet roads often have icy bridges.
  
  
• Test the traction. As soon as you pull out of your driveway, give your brakes a sharp stab and the steering wheel a yank to assess traction. AWD or stability control will fool the inattentive into thinking the roads are better than they truly are. Resample the traction regularly.
  
  
• 4WD equals go; not turn or stop. 4WD and AWD can only help you accelerate, they can't help you turn or stop. This is why Colorado ditches are clogged with SUVs bearing Texas plates.
  
  
• Definition of "spinning your wheels": working hard to accomplish nothing. Avoid wheel spin, especially when accelerating from a stop, climbing a hill or when stuck. An exception: Snow tires offer increased traction with just a bit of wheel spin. But don't buzz 'em.
  
  
• Stopping distance is drastically increased on snowy roads and braking can provoke a skid. Drive as if your brake pedal has been disconnected. If you have to brake, squeeze the pedal gently…unless you're facing an emergency.
  
  
• Stomp, stay, steer. If you have antilock brakes and face an "Oh, shoot!" situation, stomp the brake pedal to the floor, stay hard on the pedal and steer around the situation. If you don't have ABS, first quickly and firmly push the brake pedal until your tires slide. Then release pressure on the pedal until your wheels start rolling. Repeat until you hit something hard. Just like the ABS computer, your goal is to get the most grip from the grippiest bits of pavement or snow. Practice these techniques before you need them!
  
  
• Hope for a front-tire skid (which engineers call "understeer" and stock car drivers call "push"). Here's how to cope with a front-tire skid (which feels as if the steering shaft has broken): 1) Leave the steering wheel where it is; 2) lift off the gas; 3) say "Shtik!" or similar; 4) pray the traction returns before you get to the ditch. Turning the steering wheel more does nothing good and might do something very bad: If front traction returns suddenly, the car will dart in the direction the tires are pointing.
  
  
• Rear-tire skid. If your car is on the verge of spinning out (which engineers call "oversteer" and stock car drivers call "loose") and you don't have training and practice in how to handle a rear-tire skid, repeat this phrase: "I'm screwed." For the untrained in a rear-tire skid, the best choice is to pound the brake pedal to the floor and say a prayer or an expletive, or both. No more than words alone will instruct you how to hit a curveball, nothing we can write will teach you how to catch a tailslide. The main reason: While you can successfully react to a front-tire slide, you must anticipate a rear-tire slide. Another reason: Overcorrecting is common and often tragic.

Finally, be prepared for it to all go wrong.

If you crash, so can others. After the wreck, carefully evaluate the situation from inside your vehicle. It's possible others will repeat the same mistake. Never stand between moving traffic and your vehicle.

Warning! Use road flares and reflective triangles to warn other drivers of your problem. Drivers of 18-wheelers are instructed to place flares 100 and 200 feet behind their rigs when on divided highways. If there's a curve or hill, move the flares up to 500 feet behind the vehicle.

Be prepared. Carry equipment to get out of a bad situation. Here's the minimum: A tow strap, a bag of kitty litter, an army-style folding shovel.

Be a survivalist. Carry enough to survive a day or two if you get stranded: a sleeping bag, a space blanket, a poncho, several extra-large chemical hand warmers, and a couple of military-style MREs (Meal, Ready to Eat).

Our final piece of winter driving advice…If you live south of the Mason-Dixon Line when an ice storm hits, stay home.