Sideskirts Help Truckers Save on Gas

As you can imagine, truckers are interested in saving on gas. And if they save, it helps all of us. Higher transportation prices eventually work their way down the economic chain and raise the price of just about everything. The Delft University Aerospace Engineering department helped to develop a simple aerodynamic improvement to trucks to reduce their drag.

Many trucks have sideskirts, which are metal plates attached to the sides of trailers. Sideskirts block the space between the bottom of the trailer and the ground. They make in look like the truck almost rests on the road instead of having a large clear space underneath. The original purpose of sideskirts was for safety, to prevent cars jamming underneath the trailer in accidents. Delft University helped design aerodynamic sideskirts that shape the airflow. They reduce drag by keeping the airflow from going under the trailer.

Testing under controlled conditions on straight level roads revealed a 5% to 15% savings on fuel consumption. Long term real world operational tests by the transport company TNT found a 10% fuel savings. The sideskirts can be fitted to any truck. This one simple change can be deployed across the entire existing trucking fleet.

Delft also investigated the aerodynamic drag reduction possible by fitting a special "boat tail" to the back end of trucks. Although this offers further drag reduction giving another 10% to 15% fuel use reduction it is not practical for operations. Loading and unloading of cargo would be too difficult and the extra length added to the vehicle would make it unmanageable. However, the boat tail results could be used in a future where the transportation industry is rebuilt around fuel economy as priority number one.