The matter of how tyres should be changed and/or rotated had become the subject of fierce debate at recent Association of Car Fleet Operators’ meetings.
For years it has been held to be the front tyres which should be fitted with new units, when only two tyres are being replaced out of the four, and the part-worn tyres should be put on the back.
But a Kwik-Fit Fleet spokesman said: ‘The tyre industry generally recommends new tyres to the rear. This applies to both front and rear-wheel drive cars. Primarily, the justification is increased safety – particularly in the wet – where it has been demonstrated that, with the partly worn tyres fitted to the rear, their diminished water dispersal capability leads to a greater tendency towards oversteer and thus loss of control.
‘Straight line braking in the wet can be adversely affected. It is also arguable that used tyres are more prone to punctures and since it has now been established that rear deflations are more likely to cause loss of control, this is another reason for fitting new tyres to the rear.’
Kwik-Fit Fleet admitted this view may surprise many in the industry who clearly believed the now discredited ‘new tyres to the front’ rule.
The spokesman added: ‘An analysis of technical enquiries has confirmed that many customers – dealers and users alike – believe when only two tyres are replaced on a car, they should be fitted to the front axle. As a secondary benefit for the owners of low-mileage front-wheel drive cars, the switching of the partly-worn rear tyres to the front, enabling the new tyres to be fitted to the rear, creates a cycle which helps prevent their deterioration due to ageing/prolonged exposure.
‘The rear tyres wear relatively slowly and leaving them in their original positions for a prolonged period can result in the need to replace them before they are significantly worn.’
However, there are certain circumstances where the principle of ‘new tyres to the rear’ does not apply, says Kwik-Fit Fleet. These include where front and rear tyres are of different sizes, where the two new tyres have a lower speed rating or where specialist set-ups such as Pirelli’s PZero system are in use.
It is also the case with certain combinations of winter and summer tyres or on certain four-wheel-drive vehicles.