Mississauga, Ontario – The percentage of Canadian vehicles with improperly inflated tires has fallen dramatically from 2003 to 2009, but more than half of all motorists are estimated to be driving with at least one tire inflated above or below the recommended pressure, according to a new report commissioned by the Rubber Association of Canada (RAC).

The report, produced by DesRosiers Automotive Consultants from data collected in the fall of 2009, follows up on an initial survey commissioned by the RAC in 2003. Engineering students in Vancouver, Calgary, Winnipeg, Toronto, Sherbrooke and Fredericton collected data from motorists by approaching them in gas stations, surveying them, and then checking the pressure and tread depth of the tires on their vehicles.

Of the vehicles checked, 55 per cent had at least one tire that was under- or overinflated by at least ten per cent of the recommended pressure. In 2003, 71 per cent had at least one tire in this condition. The majority of respondents said that they primarily checked their tires when they looked low, or if they noticed any changes in handling characteristics.

The drop in the number of misinflated tires may be attributed to several factors, said RAC president Glenn Maidment, including education campaigns, the increasing number of vehicles equipped with tire pressure monitoring systems, and driver concerns about fuel economy. The number of vehicles with overinflated tires may be due to motorists looking at the pressure number on the tire sidewall, which indicates the maximum the tire can hold, rather than on the vehicle’s placard, which shows the correct amount.

Canadians did much better with tread depth, with only 74 of the 7,000 tires checked being 2/32 of an inch or less, considered the legal and safety minimum requirement.

The percentage of vehicles with one or more under- or overinflated tires was lowest in Fredericton, which went from 70 per cent in 2003 to 23.4 per cent in 2009. Maidment suggested that possible factors include an intensive campaign carried out by the RAC and the Lung Association educating motorists on the importance of tire pressure, as well as a 2008 crash of a school bus in the province, partially blamed on the vehicle’s tires, which killed seven students.

The highest percentage of misinflated tires was found in Calgary, which rose from 77 per cent in 2003 to 78 per cent in 2009, followed by Vancouver, which fell to 65.5 per cent from 68 per cent.

Maidment noted that improper tire pressure can cause increased fuel consumption, longer stopping distances, compromised vehicle handling and premature tire wear. For more information on tire pressure and maintenance, visit Be Tire Smart.

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