TORONTO, Ont. - Winter tire maintenance is like tire maintenance all year round. But the consequences of not maintaining your tires correctly during the year's worst driving months can be much more de...
TORONTO, Ont. –Winter tire maintenance is like tire maintenance all year round. But the consequences of not maintaining your tires correctly during the year’s worst driving months can be much more deadly.
That’s why smart fleets, owner/operators and drivers should take the following into consideration as the weather worsens:
Match the tire to the conditions
There are all kinds of commercial tires out there, for all kinds of purposes. Of course, your choice of tire should depend on what and where you’re running. A dedicated winter tire may not be appropriate for running south and back, but it may be just the ticket for running through the Rockies. And obviously a four season tire is not going to cut the mustard in heavy snow, but it could be ideal for those southern runs.
“If you’re crossing Canada in winter time, you are probably going to use a winter tire,” says Jeff Bullock, national service manager for Hankook Tire Canada. “But if you’re driving north to south you don’t want to be running a winter tire on hot pavement. What you need then is a four season.”
A good grip is what winter tires provide in spades, using rubber compounds and biting edges on more aggressive tread patterns designed to cling to wintry roads.
“A more aggressive pattern with an open shoulder is more suited to severe snow conditions, while a milder design is better for a southern route,” says Brian Rennie, director of sales and engineering with Bridgestone Canada.
Of course your tire choice should also depend on the rig you drive. If you run a straight truck or tractor with a single drive axle, an aggressive drive tire tread pattern is important. Lots of lugs will dig into snow and provide better traction. If you run a tandem-axle rig, you already have double the drive and traction, so depending on the road conditions, you might get enough grip with traditional over-the-road drive tires that are designed for good traction and long miles to removal.
One option for snowy or slushy conditions is to have your tires siped. Many tire dealers in the northern US and Canada have tire-siping machines, which cut grooves into your tires. It is generally believed that siped tires can produce a measurable improvement in traction on slippery surfaces. However, some lug tires, when siped, may be prone to tread tearing on dry pavement. And siping tires may void warranties under certain conditions. Ask your tire dealer for more information prior to siping your tires. Or buy them siped -some manufacturers are already making them that way.
Siping or no, experts say the best tires for winter driving are new ones.
“Put your best foot forward with new treads,” says Tim Miller, marketing and communications manager for Goodyear Commercial Tire North America.
Of course, fuel consumption and how many miles you can get out of a tire are always a concern for truckers, one that drives manufacturers to continually explore new ways to get good traction without increasing fuel use and decreasing mileage.
“Fuel economy is one component,” says John Overing, segment manager for the Michelin Canada’s commercial truck division. “Reducing rolling resistance has the effect of reducing fuel consumption.”
Winter tires made of softer rubber compounds and with bigger tread patterns tend to wear more quickly. Which brings us to another fundamental winter driving practice – maintenance.
Checking your tires is essential to safe driving all year round, but did you know that come winter, special factors make it even more important? Tread depth, for example, requires close monitoring, especially on dedicated winter tires.
“Winter tires wear more quickly and more irregularly,” points out Greg Cressman, director of technical services for Yokohama Tire Canada. “That’s because the compounds they’re made with are softer, to provide more grip, and the tread patterns have more blocks and sipes in it, which means tires can pick up stones and wear irregularly.”
Drivers need to be diligent about checking how tires are wearing and have tires rotated to extend their life.
“You’ve got to rotate even more with a winter tire,” says Cressman. “So you’ve got to take the time to assess the irregular wear rate, especially on the front axles.”
Wear rate is also affected by the way tires flex when they roll, bending the tire’s rubber and steel cords. The flexing generates heat, and tire wear is the result of friction created between the road’s surface and the tread as the tire rolls along. Heat is a tire’s worst enemy. Check the wear rate on your tires by rubbing your hand along the tread and sidewalls to feel for problems like flat spots, cuts, shoulder wear, bulges, sidewall damage, etc.
Proper inflation is the single most critical factor for getting the safest and longest life out of tires. It is not the tire, but the air inside the tire that carries the weight of the vehicle, absorbs shock and keeps the tire in its proper shape so it can perform as designed. A tire that is improperly inflated does not roll as smoothly or as easily as it was designed to roll. More importantly, most tire-related truck accidents are caused by improper tire inflation. Tire-related accidents are avoidable, as long as truckers maintain the proper inflation for a given tire size and load.
When tires are over-inflated, excessive wear occurs at the center of the tread because it will bear the majority of the vehicle’s weight.
Over-inflated tires tend to not absorb road hazards like debris in the road and potholes, increasing the risk of sustaining a puncture or impact damage.
That’s why tire pressure should only be checked when a tire is cold -before a vehicle is driven (or when it has been driven less than a mile). Once a vehicle has been driven, tires warm up and there is an increase in air pressure resulting in an inaccurate reading. After driving a truck, a “hot” tire can take several hours to cool down.
Checking the pressure with the truck outside, not inside in some warm garage where the temperature of the air filling the tires may not match road conditions, is ideal. Of course, checking the pressure in bitter cold presents another challenge, as moist air can come out of the valve and freeze on the spot, which makes the valve stick.
If that happens, by all means, check the pressure inside, but remember that when you fill the tires you’ll have to compensate for a greater pressure drop in extreme cold.
At 20 or 30 degrees below zero air pressure loss is even greater than normal.
In Alaska or parts of Canada when it’s 45 below, you might lose up to two psi for every seven-degree drop in ambient temperature.
If you have your truck in the shop for six hours and it’s nice and warm 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. Conversely, because air pressures fall one pound for every 10-degree F drop in the ambient temperature, if you check your pressures in the heat of the day they may be two or three psi lower the next morning after a night of cooler temperatures.
All the more reason to check tire pressure regularly, with a properly-calibrated tire gauge rather than kicking or hitting your tires with a baseball bat. You don’t thump on the hood to see if you need oil do you?
“It’s especially important to make sure you’re checking the pressure in winter because the accessibility of valves may make maintenance awkward,” says Rennie.
In other words, the guy or gal who drove the truck before you may have been unwilling to hunker down and check it him or herself. Don’t be the one to pay the price of his or her neglect.
As for chains, with chain laws in effect in some areas, it’s not a question of whether you use them, but whether you can use them without doing serious damage to your tires.
That’s why fit is all important, say th
“If your chains don’t fit properly or they’re improperly installed they can damage your tires,” says Goodyear’s Miller. “That’s why it’s important to read the instruction sheet provided by the chain manufacturer when you’re installing them. Manufacturers recommend you put the chain on, drive a few hundred feet and then retighten them,” adds Miller. “They may loosen.”
Last but not least, when it comes picking and maintaining your tires in winter (and all year round), your tire dealer is your best source for help with tread selection, maintenance tips and best practices for tire inspection, pressure checks, and chaining techniques.
Believe it or not, when it comes to getting you home safely in all weather conditions, you tire dealer is on your side.