Incorrect aerodynamic add-ons could be ‘waste of money’
Schmitz Cargobull UK technical director Derek Skinner has warned that commercial vehicle fleets could be wasting money by incorrectly specifying aerodynamic add-ons for their trailers.
Skinner has raised concerns after discovering buyers are requesting add-ons such as vortex generators and side skirts, without checking if such additions will genuinely reduce fuel costs– or if they might in fact increase them.
Aerodynamic add-ons add weight, and depending on how each trailer is used, that extra weight could negate any aerodynamic fuel-saving benefits. On top of this, the operator may even incur additional fuel costs to run a trailer that looks efficient, but actually produces more CO2because of the impact of that extra weight.
Skinner says: “There is a prevailing school of thought that you should specify aerodynamic add-ons simply because it makes a trailer look more economical and environmentally friendly to the unassuming general public, without any reference to the actual financial or environmental argument. In most circumstances, you’ll save more money simply by specifying a trailer with a lighter chassis.”
Calculating the impact of add-ons is complex and often requires knowledge of the mass density of air, drag co-efficients and their relation to object geometry, skin friction and form drag. Therefore it is no surprise that fleet operators are more likely to choose equipment that intuitively looks like it will do the job and boost fuel efficiency, without necessarily checking the facts and figures first.
Schmitz Cargobull uses a research methodology developed independently at the University of Huddersfield to simplify the calculation process, and determine the exact profiles of where a trailer will benefit from add-ons.
Skinner says: “Aerodynamic add-ons can be a benefit in certain circumstances, but any business looking to specify trailers needs to properly understand how they intend to use them, and this involves doing the research and understanding the numbers.”
He concludes: “The science shows that a trailer with full aerodynamics ends up being less economical than a standard Schmitz Cargobull trailer when its motorway miles drop below 65 to 75 per cent. If your trailer’s mileage on the motorway is sub-optimal, add-ons are probably a waste of time and money.”
