THE cost benefit to fleets of falling world tyre prices is being undermined by car makers fitting low profile tyres to increasing numbers of vehicles. Low profile tyres are more expensive to repair and replace, and their fitment - often a cosmetic rather than safety exercise - is driving up vehicles' maintenance and therefore wholelife costs.

Kwik-Fit Fleet has logged the details of hundreds of thousands of tyres removed from vehicles over the past three years, and discovered a 60% increase in the proportion of cars fitted with ultra-low profile tyres (55% aspect ratio), while the number of 70 and 75-type tyres it has had to replace has fallen by 20%.

Simon Roper, Kwik-Fit Fleet's sales and marketing director, said: 'Although on a like-for-like basis tyre costs are actually down, this increasing trend by car makers to fit more expensive lower-profile and higher speed rated tyres will have in time an adverse affect on cost. Consequently, when looking at the current reduction in tyre prices fleet managers should not automatically trim their maintenance budgets because they will find that many of the latest models have had their tyre equipment quietly upgraded by the vehicle manufacturer.'

Kwik-Fit Fleet's analysis showed that the most common tyre remains the 65-aspect ratio. Simultaneous with the falling aspect ratios of tyres are the increases in wheel sizes and tyre widths.