Design features in aid of fuel savings

Top aerodynamics

At the IAA show in Hannover, Renault Trucks is presenting an industrial design study for a long-distance vehicle, completely focused on fuel savings. Noble materials, top aerodynamics and technological innovations are combined in this vehicle, designed to give the manufacturer a long-term direction for its fuel-saving research.

“The work on CX/03 is an industrial design study and not a study in style”, warns Hervé Bertrand, designer at Renault Trucks. This vehicle is completely in line with the previous research performed by the manufacturer in this area, such as Optifuel Lab. “The idea is to embody Renault Trucks’ fuel-saving ethos”, continues Hervé Bertrand, “and give the company a long-term orientation for future research.” This is why each element of the vehicle has a very precise function, mainly driven by aerodynamics and efficiency.

The front grille, first of all: made solely of a carbon fibre structure with aluminium, it looks like the truck’s exoskeleton, suggesting both lightness and robustness. In the central section, a retractable sliding panel descends into the lower part as vehicle speed increases. Further down, an air dam at the bottom of truck does the same thing to reduce ground clearance, and 3 aerodynamic blades push the airflow out to the sides. The wing mirrors are minimalist and held by two profiled tubes. For these and all other elements, the objective is the same: to improve air penetration, and thereby enhance consumption reduction.

Along the same lines, the cab steps, a source of turbulence, and the tractor wheels, are covered so as to improve airflow. In the cab, the slope of the windscreen that the designers call “Pillar A”, is 12°. It delivers the optimum aerodynamic compromise. Also, it is slightly sloped at a halt to give the truck a dynamic feel. “We wanted to help people understand at first glance that all the elements of this vehicle are designed to be light, efficient and aerodynamic”, says Hervé Bertrand.

Renault Trucks CX03But the aerodynamics of the truck are not just in the tractor. The trailer plays a key role too. By using elements from previous research, such as Optifuel Lab, Renault Trucks dreamt up a trailer with a curved roof similar to the water-drip design, with side faring encompassing all the wheels and the rear deflectors. Also, the connections between the tractor and the trailer have received particular attention, given that the space between the two generates substantial turbulence. “To reduce it as far as possible, we imagined a system of adjustable farings,” explains the Renault Trucks design director. “When the vehicle is on the highway, the cab is one unit with the trailer, and the airflow is uninterrupted. On the other hand, at low speeds, to make manoeuvres easier when the farings serve no purpose, they retract.”

Renault Trucks CX03As a real working tool synonymous with efficiency, reliability and fuel saving, CX/03 must not be considered a cold monster. “We didn’t want this thoughtful side taking away the passion”, remembers Hervé Bertrand. “In order to bring a bit of warmth to the machine, we decided to add an aluminium plaque on the side of the cab with a red fade. Red, the colour of passion, is also the colour of Renault Trucks.