Why does tyre wear matter?

As a tread wears the tyre’s rolling resistance declines primarily because the tyre loses about 15% of its mass, the tread band accounts for 25% of the tyre’s weight. Numerous studies have examined this relationship and have shown that the rolling resistance of a tyre can be expected to decline by up to 30% over the tyre’s tread life. Typically, 12 to 20% of the energy in the fuel tank is ultimately transmitted as mechanical energy to turn the wheels and one third of this is consumed by rolling resistance. On average a 10% reduction in rolling resistance equates to a 1-2% reduction in fuel consumption.

Despite recent advances in tyre design and compound formulation, such as the introduction of energy saving tyres, very little improvement has been made in tyre management tools and techniques. Fleet managers still rely on manual inspection and tread depth measurement made with manual gauges which are inaccurate and suffer very large gauge R&R (repeatability and reproducibility) variation.

Consequently fleet operators incur significant wastage of fuel and tyres associated with poor tyre management and premature tyre replacement. Field trial date shows that improving tyre management and running an additional 1mm on worn tyres equates to a fuel and tyre saving of 5p per km for an HGV tractor unit. That adds up to a typical saving of £220,000 per year for a fleet of 100 tractors.