Re: 09 FEHL Tire Presure for North East Winters?
Higher pressure means a smaller contact patch, leading some people to conclude "less traction". But the smaller contact patch means more pressure on the available square-inches of rubber on the road. That higher pressure is what gives larger cars and trucks better traction on slippery roads, and you approximate this advantage by increasing tire pressure on lighter vehicles.
For loose-snow traction, more rubber on the road can give you better results because there's more tread to dig into the snow and pull the car ahead. For ice-traction, the thin film of water that builds up under the tread surface is what makes the icy roads so slick. This doesn't change regardless of how much air pressure is in the tires.
If your driving involves frequent driving in heavy snow or icy road conditions, dedicated winter tires will give you better traction without significant fuel economy penalty. During the winter, my wife and I drive many miles in the Poconos, and so we use winter rubber to maintain control on the steep mountains and death-curves when they're covered in a frozen glaze. We run these winter tires at 40psi and they stick to the road like flypaper.
While this may sound like an ad or testimonial for snow tires, the real reason for sharing the information is to illustrate that it is the tire's tread pattern and its rubber formulation that dictate winter traction, and setting tire pressures anywhere between what the placard says and what the sidewall says will not have a major effect on traction.
If you choose to boost tire pressure before winter weather arrives, simply drive carefully the first few miles on the slippery stuff, preferably in a loop, and note any control issues. Then reduce the pressure and drive the same loop again. If there is no substantial difference in handling, boost the tires up again. If the control difficulties arise at the higher pressure and the car stabilizes at lower pressure, keep the lower pressure.