A trailer, fitted with Serco’s aerodynamic accessories, had, on average, achieved a notable fuel saving of 2.5% during road tests conducted last month, said truck body and trailer manufacturer Serco MD Clinton Holcroft at the Johannesburg International Motor Show last month.

He noted that this equated to a R22 700 saving on each trailer, based on a trailer travelling 15 000 km a month at the current diesel costs.

“Two 15 m trailers, both hauled by German automobile manufacturer Mercedes-Benz Actros horses, were used in the tests carried out in collaboration with information and related services provider for the management of mobile assets Mix Telematics,” he noted.

Holcroft explained that a standard trailer was compared with a trailer fitted with side skirts and a roof diffuser.

“The trailer side skirts – developed by US-based practical fleet fuel-savings company Freightwing – redirect air past the running gear and the under- side of the trailer, while the recessed roof diffuser reduces back pressure and wind drag behind the vehicle,” he said.

Holcroft explained that the wheel alignment, tyre pressure and driver habits were monitored throughout the testing to eliminate variables. Each trailer was loaded with 24 t of cargo to closely mirror realistic transport conditions, and the average speed travelled was recorded at
67 km/h.
“To ensure absolute accuracy, three methods were used to measure fuel consumption – fleet telematics, on-board diagnostics and brim-to-brim assessments.

“Several identical runs of 300 km each were completed between Durban and Richards Bay under closely monitored and controlled conditions to determine the aerodynamic benefits of the Eco trailer kit to fuel economy,” he stated.

Holcroft added that the greatest obstacle for most transporters in deciding whether to fit such fuel-saving accessories was the difficulty of accurately measur- ing whether there were in fact fuel-saving benefits under normal operating conditions.

“The list of variables is extensive and includes varying cargo weights, driver habits, weather conditions, tyre pressures and traffic conditions, as well as truck, tractor, engine and drive-train wear,” he said.

He further stated that the idea of the road test was to monitor and control the variables to measure the benefits and provide clarity for transporters aiming to save costs and reduce their carbon emissions.

‘The tests have clearly shown that the accessories do save fuel and, at higher speeds, the fuel savings are expected to be even greater. “We are excited about the outcome and the potential benefits it creates for our customers,” he noted.

Holcroft pointed out that continually rising fuel costs currently comprised about 40% of the overheads of transport companies.

“What makes our aerodynamic accessories even more attractive is their relatively low cost, which makes the expected payback period less than a year,” he concluded.