Here are a few tips from Transport Canada to maintain proper winter tire inflation:
• Measure your tire inflation at least once a month.
• Measure the pressure when the tires are cold (after two hours of non-use or less than two kilometres of driving). Tires lose pressure when the air temperature gets colder.
• Inflate your tires to the recommended pressures printed on the label inside your car or in your owner's manual.
• Use a high quality gauge such as those sold at automotive supply stores.
• Under inflation increases rolling resistance, which reduces tread life and increases fuel consumption. It can also lead to sudden tire failure. Without enough air, the sides of a tire bend and flex too much. This builds up heat, which can cause serious damage. Operating a vehicle with just one tire under inflated by 56 kPa (8 psi) can reduce the life of the tire by 15,000 km and can increase the vehicle's fuel consumption by four per cent.
• Over inflation can be a problem, too. An overinflated tire rides on just the centre portion of the tread. The smaller contact area means reduced grip on the road. This can lead to a harsh ride, handling issues (such as steering and stopping problems) and increased wear on tires and suspension components.
Transport Canada has posted these and other tire maintenance tips on its website:
http://www.tc.gc.ca/roadsafety/tp/tp2823/inflating.htm
Keep your car's winter tires in top condition by checking the inflation levels often. Keep the air pressure in your tires at the proper levels.