Maximum speed. Increase in fuel consumption when driving at high speeds is due mainly to the sharp increase in the resistance of air, because power consumption to overcome this resistance increases as the cube of the speed. For example, when the speed of 80 to 95 km / h increasing power consumption by up to 80%. Thus, in order to save fuel maximum operating speed above 90 km / h are not recommended.
The shape and size of trains or cargo. Air resistance is largely dependent on the frontal surface area and degree of circularity train. Thus, in the case of a semi-trailer with the vertical side edges of the air resistance is much greater than in the presence of a semi-trailer with smooth side surfaces with the same frontal surface area.

Aerodynamic studies of English used interrogation automotive industry association (MIRA), showed that the rounded corners container size 2,45 x2, 45 m radius of 76 mm drag is reduced by 25%, and a radius of 152 mm - 70%.

In recent years a proliferation of deflectors (deflectors) for trucks, which are installed on the roof of the truck and in the area of ​​space between the back wall * cab and the front of the semitrailer. The first such devices were used in the U.S.. They improve the aerodynamic qualities of the semitrailer and prevent the occurrence of spurious turbulence in the space between the cab and trailer. According to reports, reducing fuel consumption by 4.5-5% by improving aerodynamics train for 6 months. pays for the cost of the whipstock.