Fleet operators may not be getting the fuel savings they require from the tyres fitted to their vehicles an automotive emissions and fuel consumption expert claims.
Research from Emissions Analytics indicates that the tyre-rating label, mandated by the European Union, may not be telling the full story over the efficiency savings to be had by fleet operators.
Their tests show that in some instances lower rated tyres could perform just as well as higher rated versions. The research suggests that the relationship between rolling resistance and fuel economy is not necessarily linear, so expected fuel savings may not materialise.
Nick Molden, Founder and CEO of Emissions Analytics, explained, “Our test found that at mid-range speeds, some F-rated tyres can perform as well as B-rated tyres.
“Tyre efficiency labels don’t provide enough information for buyers to make an informed choice.”
The tests undertaken saw a set of F- and B-rated tyres used on the same prescribed route and at a range of speeds from 40mph to 70mph.
The results show that if a vehicle is more likely to be used on urban routes, then the higher rated tyres are unlikely to produce much of a fuel saving over lower rated versions.
However, if a van or truck covers a substantial number of motorway miles then a significant improvement is noticeable. The research showed that the B-rated tyres achieved a saving of 3.8% on fuel and a CO2 reduction of 3.4% on average, but the major differences were noticed at higher speeds, with the B-rated tyres making efficiency savings of more than 12.9% at 70mph.
Molden believes these indications show that, despite the EU mandated tyre label including reference to a rolling resistance co-efficient expressed as a fuel efficiency rating, there is no correlation between the two. He says that better testing and modelling of this system is needed, so that fleet operators are able to make better informed decisions.
Countering the concerns, Andy Mair, Head of Engineering at the Freight Transport Association, feels that the tyre ratings aren’t so crucial to fleet managers but serve a greater purpose to the passenger car market.
“The road transport sector in recent years has seen an increasingly focused approach on tyre selection and maintenance, and commercial fleet managers are well ahead of the game when it comes to specifying tyres for commercial vehicles.
“The labelling regulations do of course provide valuable like-for-like guidance, which enables buyers to see at a glance the specification of a particular tyre.”
