For a fleet with 1,000 cars which have under-inflated tyres this could mean paying out an extra £6,000 every time their tanks are filled with fuel.
And drivers who neglect their responsibilities are costing companies further as under-inflated tyres wear out about 30% more quickly than those with the correct pressure. In a bid to stamp out the problem, fleets are being encouraged to financially penalise drivers who fail to take the issue seriously.
Executives at ATS Euromaster, which carried out the research, say the problem has been overlooked for too long.
Product manager Martin Barber said: ‘While the safety message surrounding driving with the correct tyre pressure is paramount, in order to encourage drivers to take a greater responsibility we believe drivers need to be hit where it hurts most – the pocket.
‘The reality is that unless a tyre is checked once every two weeks a motorist could well be driving an unstable vehicle that is costing them extra.
‘While the issue is cause for concern for all motorists, fleet drivers should really take a greater responsibility for their vehicles.’
The company says a number of factors can cause a drop in pressure including natural leakage of air through the walls of a tyre and a drop in ambient temperature. A spokesman for the Tyre Industry Council added: ‘Highlighting the fact that failing to run a car tyre on its recommended tyre pressure actually hits a motorist where it hurts most, in his or her pocket, re-emphasises its importance to check tyre pressures regularly.’
A recent survey estimated that as many as 800,000 of the UK’s three million company cars, and one million vans, were running on at least one unsafe tyre, with many of them either under or over-inflated.