Tyres can account for a third of a fleet’s total running cost, but this impact can be mitigated by an effective tyre policy. Alisdair Suttie reports.
Having an effective tyre policy in place can save fleets substantial amounts of time and money, contribute to a successful environmental policy and help protect employees.
Department for Transport’s figures show that in 2012, 194 drivers were killed or seriously injured on the UK’s roads due to faulty, under-inflated or illegally worn tyres - amost four every week.
Implementing an efficient tyre policy can be left to a fleet management company, but it still pays to understand how a good tyre policy works.
This is especially important when tyres can account for around a third of a fleet’s total running costs, coming second behind fuel.
Balancing cost versus efficiency is a dilemma in all areas of fleet management, but tyres are particularly important as the only part of the vehicle in contact with the road and, as such, often the most crucial element in keeping the vehicle’s occupants safe from harm.
Here, we look at the three main areas of concern when considering a robust tyre policy: tyre tread depths, punctures and tyre choice.
Tyre tread depth
The legal minimum tyre tread depth in the UK is 1.6mm, which is about the same as the dotted shoulder around a 10p piece.
While this is the legal minimum requirement, every fleet, tyre company and leasing company Fleet News has spoken to changes its vehicles’ tyres at no less than 2mm.
Some fleets change tyres at 3mm, but this carries a cost implication (and environmental impact) and this practice is generally only adopted with vehicles that perform in particularly extreme road and weather conditions.
A good quality tyre is still performing very well at 3mm of tread depth, delivering strong braking, cornering and wet weather performance so the car feels stable.
Most new tyres come with 8mm of tread depth, so a fleet that changes its tyres at 2mm has a 6mm operating window. Depending on the type of tyre, vehicle and road conditions, this can mean as much as 25,000 miles of driving on a typical set of tyres. If fleets were to implement a 3mm change policy, the cost implications would be huge as it would effectively increase tyre costs by one-sixth. Applied across any fleet, that would put great pressure on budgets.
However, there are other factors that come into play with tyre wear, such as driver behaviour and the vehicle itself. The tyres on the driven wheels will generally wear more quickly than those on an undriven axle, so a Ford Focus will get through its front tyres more rapidly than the rears. The opposite applies to rear-wheel drive cars.
While some will advocate swapping the tyres from front to back to eke out the maximum wear from both pairs, this is not a recommended practice. Far better to replace the worn tyres as they reach their 2mm tread depth and monitor the less worn set so they can be replaced as necessary.
With the profusion of mobile tyre fitting services available to fleets now, there really is no need to risk running a car with unevenly worn tyres.
Another reason for avoiding swapping tyres front to back is fuel economy can be adversely affected by up to 15%, which amounts to a substantial sum when applied to larger fleets.
Peter Lambert, fleet director for Kwik Fit, says: "Adopting a 2mm replacement policy ensures that drivers have a period of time to replace tyres before they risk driving on an illegal tyre with a significant impact on braking performance and stopping distances."
There are other reasons to consider running tyres to a tread depth of 2mm before replacing.Malcolm Roberts, fleet services manager at Hitachi Capital Vehicle Solutions, points out: "We are aware of some tyre manufacturers who recommend changing tyres are 3mm.
"However, we believe there is an environmental impact through replacing tyres earlier due to the cost of producing a new tyre and the safe disposal of the old tyre.
"We also believe tyres are at their most fuel efficient at 3mm, having less rolling resistance but still with good performance."
To make sure a fleet vehicle is getting the most from its tyres and they are scheduled top be replaced at the right time does require monitoring. While some fleets have a policy of checks, either by the driver or a mechanic, often this is an area left to the discretion of the driver.
David Howe, fleet services manager, at HiQ, says: "Good tyre husbandry is vital and it should not be left to services or an MOT check. Regular checks by fleet drivers are essential and fleet managers should encourage this. The leasing company may well also enforce this, so it makes sense to have this procedure in place so that it becomes a habit and good practice."
These checks should not just be for tread depth, which can easily and quickly be ascertained by the wear indicators set into the tyre’s tread blocks. Drivers should also be checking for any obvious damage to the tyres, such as cuts or bulges by kerbing, as well as potential punctures from stones or screws.
By reporting damage early, it can prevent a puncture or even a collision, with obvious benefits for safety and reducing downtime for repairs.