A joint study conducted by Volvo Trucks and Michelin has found that a combination of good tyre choice, correct pressures and wheel alignment can save fuel by up to 15%. This could then equate to huge savings of nearly £7,000 per vehicle per year.

The test was 2 weeks long, covered 1,000km (621 miles) and was conducted in Hällered, Volvo’s Swedish test circuit. The trucks used were two Volvo FH 4x2s and each had a 500hp 13 litre Euro 5 engine. The trucks both weighed 40 tonnes gross from fully loaded van-bodied trailers. One truck was driven with a number of different incorrect tyre pressures, types and wheel alignments and one was driven with optimal tyre pressures, types and wheel alignments.

The exact speed of the trucks, tyre wear, rolling resistance and pressure was monitored with specialist equipment and adjustments were made by test engineers for confounding variables such as wind, rain and temperature.

The test was independently verified by a representative from SP (the Technical Research Institute of Sweden).  It was also maintained under realistic conditions with no exaggerations “because real life is bad enough”.

The test results found that tyre choice was the key factor to variations in fuel consumption, as it was responsible for an 11% difference. The next factor was wheel alignment with the finding that misaligned wheels used an extra 2.5% fuel. Lastly tyre pressure was found to affect fuel use by 1%. The results were explained by the fact that misalignment and lack of inflation as well as tyre type can cause an increase in rolling resistance.

These results not only apply to long-haul but can be extended to construction vehicles too.

Reduced fuel consumption of course also means reduced CO2 emissions. Considering that commercial trucks are responsible for 30-40% of transport emissions and 22% of the UK’s carbon dioxide comes from its roads, any savings made become very worthwhile.

It is not just fuel and CO2 that are saved but the evidence also suggests that tyre wear and durability is improved from using quality, well maintained tyres. This is because rolling resistance is the result of the friction that occurs when the tyre comes into contact with the road. This friction then transfers heat and kinetic energy to the surface of the tyre, breaking chemical bonds and freeing tiny particles. Tyres that wear down more slowly don’t just make savings on replacements and the resources to make them but will also release less particulate matter into the air from the tiny pieces of worn tyre. Particulate matter (PM) has been found to be very dangerous to human health; see the website of the Healthy Air Campaign for more information.

This study is an important demonstration of what a difference using the right tyres can make as well as ensuring correct maintenance. The Campaign for Better Tyres welcomes it as part of the growing body of scientifically verified evidence supporting our campaign message. We hope that this study will encourage more fleet owners and managers to ensure they have a good, robust tyre procurement and maintenance policy as now they have another reason to be confident in the potential savings.