New fuel saving trailers

28/11/2011

Mercedes Benz, the van and truck maker of choice for OSE, have recently unveiled its new 13.6m trailer which they claim reduces wind resistance by 18% and fuel consumption by almost 5%.

The new trailer is to be presented for the first time at the ‘Trailer 2011’ logistics show in Kortrijk, Belgium.

The modifications to the trailer come after a detailed design study which investigated the ways in which the enormous drag a 13.6m trailer produces can be reduced. The study went into great detail on each individual design feature, taking a highly efficient view on each one.

The design features of the new trailer, named the ‘Aero Trailer,’ were developed by Mercedes Benz’s highly experienced team of developers and aerodynamicists as well as commercial vehicle design department. The same team of developers, aerodynamicists and commercial vehicle designers had already been successful in the design of the new Mercedes Benz premium truck, the Mercedes Benz Actros. The new vehicle has a wind resistance of 12-15% lower than that of the previous vehicle model. The new trailer shares a number of similar features.

The new features contributing to the decrease in wind resistance include a front airdam on the trailer which reduces the distance to the tractor unit and lowers the wind resistance by one percent. Also, side trim panels that are slightly drawn-in at the front and characterised by an opening at the rear which steers the air in the direction of the rear diffuser contributes to an 8% improvement in air resistance. In addition, the diffuser has the shape of a parallelogram and links up with the underbody panelling which improves the wind resistance by 1-2% as well as a new rear end taper measuring just over 400mm in length is very important to the new aerodynamic design. It features folding elements to facilitate access to the load compartment and improves wind resistance by a further 7%.

The reduction in wind resistance caused by the newly design features has a direct effect on fuel consumption. Overall the new aero trailer lowers wind resistance of the entire semitrailer tractor by approximately 18% which, according to Mercedes Benz, results in a reduction in fuel consumption of almost 5% in real-life road traffic. This equates to, in the case of an average mileage of 150,000km a year, a saving of approximately 2000 litres of diesel fuel a year and also reduces the burden on the environment of over five tonnes of CO2 emissions per year.

Most importantly, the freight capacity of the aero trailer remains unaffected with the familiar box measuring 13.6m in length, 2.55m in width and 4m high. However, the aero trailer is restricted as its length is currently half a metre over the permissible limit due to the tail-end extension. Mercedes Benz claims the handling and manoeuvrability are not in any way compromised by the taper, despite the additional length.

Mercedes says it is here that changes to legislation are necessary, as in the case of tail lifts and transportable fork-lift trucks, for instance, where exceptions of a similar magnitude are already granted and, with a ten year test already under way in the UK for larger trucks, Mercedes Benz are hoping for a common sense compromise for vehicles that plainly have a beneficial effect on emissions and fuel consumption yet vary so little from the accepted current norm.