The study was conducted using two Volvo FH 4x2 trucks, each equipped with a 500 hp., 13-litre Euro 5 engine, and hauling a fully loaded trailer. The rigs each weighed 40 tons. One rig was driven with a variety of incorrect wheel alignment settings while the other used optimally aligned wheels and with standard tractor and trailer tires supplied by Michelin.
“All the conditions tested were realistic, no exaggerations were allowed,” said Arne-Helge Andreassen, business area manager for tyres and wheel alignment at Volvo Trucks’ Aftermarket Department. “Real life is bad enough. Diesel consumption increases dramatically if the wheels are not entirely parallel. And this applies to all vehicles, for construction and long-haul operations too. A trailer with a rear axle angled to the right will roll diagonally across the road and its side panels will operate as a sail that traps the wind.”
The test truck was also run with various tyres and various tyre pressures. The testing was reviewed by Mats Lidbeck from the Technical Research Institute of Sweden, who served as an independent auditor of the testing.
The companies found several interesting facts, not the least of which is that using the correct tire can cut fuel consumption 11% with correct tire inflation reducing it another 1%.
“One-third of fuel consumption stems from the tires’ rolling resistance,” said Jacques de Giancomoni, technical account manager at Michelin. “Having the right tires is of paramount importance. And checking tire pressure - which has a significant effect on fuel consumption - is also important.”
“There is a lack of awareness in the transport industry about the importance of checking tires and wheel alignment, on both the truck and the trailer,” said Andreassen. “At our dealers, we can help haulage companies check the entire rig and correct any problems. If everyone did this, it would have a significant impact on carbon dioxide emissions.”
So what does this study ultimately say? Despite the fact that it was carried out in Europe with European trucks, there is no doubt that if a similar study was conducted here, we would see similar results.
The keys to cutting carbon emissions when it comes to tires are simple: Low-rolling resistance tires, maintaining proper inflation, and keeping vehicles aligned. Managers spend plenty of time spec’ing the right equipment for their application. It’s also important to spec the right tires and then properly maintain them once the vehicle hits the road.
And if for some reason you’re not concerned with the environment, there is another benefit that will get your attention: less fuel used which translates to cash saved.
Every little step helps.