Van users may be increasing fuel costs by overloading their vehicles, according to TyreSafe, a UK tyre safety organisation.

The latest VOSA effectiveness report has showed that the number of LGV users found by traffic enforcers to be overloading their vehicles rose from 66.9% in 2008/09 to 72.7% in 2009/10.

TyreSafe warned that unless operators compensate for heavy loads by increasing tyre pressures to the recommended levels, their tyres will wear out quicker, fuel consumption will increase and safety may be compromised.

Calculations from one TyreSafe member show that when tyres are under-inflated by just 20% (around 6psi), 3% more fuel is used.

“Overloading in itself is a serious safety hazard which operators must address, but even if they are carrying legal loads, they should ensure their tyres are adjusted and inflated to the correct pressure,” said TyreSafe's chairman Stuart Jackson. “If tyres do not contain enough air for the load being carried, they are much more likely to experience a rapid deflation which can result in a terrifying accident. There are also  significant downsides such as longer stopping distances, reduced stability, increased tyre wear and higher fuel consumption.”

Tyres which are overloaded or under-inflated cause excessive heat to build up inside the tyre, which significantly increases the likelihood of experiencing a dangerous blowout, particularly on high speed motorway journeys.

When under-inflated, the tyre’s contact patch with the road surface is reduced to two smaller areas towards the outer edges of the tread. With the full vehicle load placed on these two areas, the tread wears at a much higher rate forcing replacement much earlier than would be otherwise needed. By running tyres at just 80% of the recommended pressure, operators can expect tyre life to be reduced to around 75%. If the pressure falls to 60%, they can expect to achieve just 35% of the potential mileage from the tyre.

TyreSafe has launched a dedicated van tyre safety section on its website, with a downloadable van tyre safety leaflet. For more information, visit