Slipping in safety
It seems tyre safety has been blown away in “the windy city”, having dropped alarmingly since 2013. This is the word from Bridgestone’s Tyre Check team after collating the results of their most recent survey of tyre pressure and condition in Port Elizabeth.
The survey, which was conducted in July in the car park of the Pick n Pay store in Moffat Park, showed that the percentage of tyres that were safely inflated had dropped from 89 percent in 2013 to 82,5 percent.
“We’re extremely concerned about this drop, because it means that motorists are not checking their tyre pressures regularly enough,” says Desirée van Niekerk, Bridgestone’s PR manager. “The Port Elizabeth survey also showed that other areas of tyre safety have slipped compared to last year.”
Each tyre, out of the 300 vehicles surveyed, was checked for pressure, condition and mixed tread patterns. The results are recorded on a survey leaflet, which is left under the vehicle’s windscreen wiper for the driver.
Bridgestone states that some of the key figures to come out of the Port Elizabeth survey are that only 0,67 percent of tyres are dangerously under-inflated (below 130 kPa or 1,3 bar). “However, this is still significant, because it means that possibly as many as one in 37 vehicles, on Port Elizabeth’s roads, has at least one tyre which is so badly under-inflated that it is at great risk of overheating and sudden tyre failure,” the tyre manufacturer points out.
More than four percent of tyres were in the hazardous bracket, with inflation pressures between 130 and 160 kPa. And 9,67 percent of tyres surveyed were between 160 and 180 kPa. “These tyres will show faster wear, especially on the shoulders,” adds Bridgestone.
“Roadholding and braking will also be affected, and the extra heat generated by under-inflated tyres comes at the cost of increased fuel consumption. The 2,92 percent of tyres that were severely over-inflated (in excess of 290 kPa) will also show excessive wear, as well as reduced roadholding.”
The number of tyres that showed cuts, bruises, bulges or tread worn to the legal limit held steady – the 2014 survey showed that 7,17 percent of tyres fell into this category, a small change from seven percent in 2013.
“However, a whopping 14,33 percent of tyres were found to have ‘mixed tread patterns’ , a considerable jump over the four percent of 2013,” states Bridgestone.
Van Niekerk adds: “Vehicle roadholding characteristics are designed for identical tyres on all four wheels. Mixed tread patterns front-to-rear usually results in a predictable change in the vehicle’s characteristics, but mixed tyre tread patterns left to right can affect safety through unbalanced roadholding.”