Be tire smart by making sure your tires have sufficient tread depth and are properly inflated
With the summer driving season upon us, Canada’s tire makers want drivers to get into the groove with their tires by measuring tread depth.
Why is tread depth important? When even a moderate summer thunder storm strikes, the traction and stopping capabilities of tires nearing the end of their service life can be substantially reduced, particularly at highway speeds.
Sufficient tread depth is what allows tires to grip rain covered roads and provide the traction required for control and braking capability.
As every driver who has ever had to make a panic stop on a rain-slicked highway knows, the ability to stop quickly can spell the difference between a stressful driving experience and a serious collision.
Longer stopping distances, hydroplaning
When the tread becomes too worn and the tread grooves become too shallow, a tire’s ability to efficiently evacuate water is considerably reduced. This can lead to hydroplaning where the tire loses contact with the road’s surface and floats on top of the water, resulting in a loss of tire grip or traction. When this occurs, the distance needed to stop in a panic braking situation increases significantly. Hydroplaning, which is extremely dangerous, can also result in a complete loss of control.
A recent U.S. tire study, conducted by Tire Rack, demonstrates how dramaticaly stopping distances can increase on wet roadways depending on tire wear. The study measured panic stopping distances at highway speeds on wet asphalt (equivilant to a moderate rain shower), comparing new tires with partially and fully worn tires.
Not surprisingly, the shortest stopping distance was on new tires with 10/32nds of an inch (8mm) of tread depth. In the demonstration, tires three quarters worn to a tread depth of 4/32nds of an inch (3.2mm) increased the stopping distance, taking a further seven car lengths to stop. On fully worn tires with tread depth at the legal limit of 2/32nds of an inch(1.6mm), the stopping distance was lengthened by yet another seven car lengths.
This study shows that, over the first three quarters of tire tread life, the stopping distance can increase by seven car lengths. It also illustrates how stopping distance can lengthen further over the last one quarter of tread life (from 4/32nds (3.2mm) to 2/32nds (1.6mm) of an inch) by another seven car lengths!
Most tire makers generally recommend that drivers replace their tires before the legal limit of tread wear is reached to ensure their vehicle’s tires always have excellent stopping power, particularly on wet road surfaces.
“Keeping track of your tires’ tread depth by taking regular mesurements is vital to safey and making an informed decision about when to replace your tires,” says Glenn Maidment, president of The Rubber Association of Canada, which represents tire makers. “Motorists who are unsure if their tread depth is sufficient for wet driving conditions should consult their local tire professionals.”
Proper tire inflation
Proper tire inflation is a safe driving essential in all driving conditions. Tire under-inflation increases stopping distance and hampers performance by lessening vehicle stability, particularly when cornering.
Tire makers strongly recommend that drivers measure their tire pressures monthly to ensure they are always inflated to the vehicle manufacturer’s recommendation.
”Taking five minutes each month to measure and, if necessary, adjust your tire pressures safeguards optimal tire performance,” says Maidment. “Beyond being the leading cause of tire failure and premature wear, under-inflation also wastes fuel and harms the environment.”
An under-inflated tire wastes fuel because it does not roll as easily as it was intended. The increased rolling resistance, which worsens with the degree of under-inflation, requires the vehicle’s motor to burn more fuel to push the vehicle down the road.
According to the RAC, a motorist who drives 20,000 kilometres per year can save as much as $100 in fuel simply be ensuring their tires are inflated to the right pressure. For drivers who log many more kilometres over the course of a year the saving can be considerably higher.
The price tag for ignoring tire inflation is high. Canadian drivers rolling on under-inflated tires are expected to waste more than 500 million litres of fuel in 2013. That is enough fuel to power 250,000 vehicles for a full year. All that wasted fuel will release an additional 1.2 million tonnes of carbon dioxide into the atmosphere.
According to RAC research, one third of Canada’s 21 million vehicles have at least one under-inflated tire and only 30 per cent of drivers measure their tire pressures monthly.
Canadians can learn more about caring for their tires by visiting www.betiresmart.ca. A standout feature of the site is a new series of engaging videos aimed at educating young drivers about proper tire maintenance.