Tyre Aging Tests Given the Nod

In the US a 33-member task force comprised of tyre manufacturers, automotive industry officials, independent experts and government have given their endorsement to a proposal to test the durability of aging tyres. This test, which the National Highway Traffic Safety Administration (NHTSA) hopes to implement in 2007, will most likely involve placing tyres in a high oxygen environment and subjecting them to temperatures of up to 66° Celsius (150 degrees Fahrenheit) for periods of 8 or 10 weeks.

This task force, the Aged Tire Durability Task Group, was formed in 2002 in order to “create a scientifically valid” test of tyre durability. In addition to the heat testing, the group is also promoting the implementation of a separate durability test, in which tyres would be run at about 75 mph (120 km/h) for more than 30 hours at a time.

The Rubber Manufacturers Association is supportive of the NHTSA’s plans to introduce testing that, in the words of an Association spokesman, “will give some assurance that a new tyre will last over time.” The long-term durability of tyres has been a notable issue in the US since Ford spent in the vicinity of US$3 billion (£1.5 billion) replacing Firestone tyres it claimed were prone to failure and responsible for a number of fatal accidents involving Ford Explorers.

It is yet to be determined whether tyres have a fixed lifespan. A number of major car manufacturers have put their backing behind guidelines that tyres should only be in use for a maximum of six years. Safety advocates are adamant that the NHTSA should set tyre expiration dates as soon as possible.

Under current US legislation the NHTSA will not require tyremakers to print the date of manufacture on the outside of tyres until September 2009.