Winter Tire Tips
August 25, 2008 With temperatures continuing to dip and clouds beginning to form, it won’t be long till Old Man Winter’s wrath of rain, sleet and snow begins to pelt roadways. Combine nature’s moisture with cold temperatures and you have many factors to consider in preparing for winter driving.
Below are tips from Tim Miller, Goodyear’s commercial tire marketing communications manager, on how to prepare for winter driving.
Choose the Right Tread
Having an “aggressive” drive-axle tread pattern is very important for single drive-axle tractors and straight trucks. A pattern with lots of lugs will dig into snow and provide better traction. If you run a tandem-axle rig, you’re doubling the drive and traction and, depending upon the severity of weather, can get enough grip with traditional over-the-road drive tires that are designed for good traction and long miles to removal.
The key thing for traction is having lots of gripping edges for traction improvement in snowy or slushy conditions. Ice presents its own set of challenges that even the most aggressive tires can’t handle. One way to help fight ice and slippery road conditions is to have your tires siped. Many tire dealers in the northern United States and Canada have tire siping machines, which cut grooves into your tires and help grip. Studies at Goodyear have shown tires that have been siped have measurable improvement in winter traction. However, some lug tires, when siped, may be prone to tread tearing on dry pavement. Ask your tire dealer for more information prior to siping your tires.
Tread Depth
It’s common sense that a tire with lots of tread will have more traction than a tire on its last 32nds. While most fleets remove tires with a worn tread depth value of 4/32nds in the spring and summer months, that’s not a recommended practice in the winter. In the winter, it’s recommended that tread be removed at 8/32nds. Tires that are pulled early can be placed on trailers or put in racks until spring arrives.
Checking Tire Pressure
It’s tried and true advice: check your air pressures before the vehicle begins its day at work, when the tires are cold. Because air pressures fall 1 pound for every 10˚F drop in the ambient temperature, if you check your pressures in the heat of the day, they may be 2 or 3 psi lower the next morning after a night of cooler weather.
But what happens when the temperatures are extremely low – like, 20 or 30 degrees below zero?
Air-pressure loss is even greater than normal. In Alaska or parts of Canada, when it’s 45˚F below, you might lose 2 psi for every 7˚F drop in ambient temperature. If you have your truck in a warm shop for six hours and you fill to 70 psi, the inflation pressure may not be adequate for the kind of weight you’re hauling. You might need 90 psi or more.
Another challenge: When you take an air-pressure reading, you get moist air coming out of the valve stem and freezing on the spot, which can cause the value to stick. If you encounter bitter-cold weather and you need to check your air pressures, do it in the shop where it’s warmer and you won’t risk a stuck valve. When you fill the tires, just remember to compensate for the greater pressure drop that happens in extreme cold.
A Word On Chains
If you do proper chain ups, you’ll have no negative impact on tire life. But if you don’t pay attention and chains are not tight enough, or if you run on chains after they’re needed, your tires will face the consequences and suffer an early grave to the scrap pile. If you have new drivers, training on chaining up should be conducted. Usually, you can call on your tire dealer for assistance in putting together a winter driving class, which will include information on best practices for chaining tires.
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