The German company Jost introduces a patented roof diffusor for trailers that promises fuel savings up to 4%. The drag behind the trailer is supposed to be 50% lower when this device is mounted on the roof.
JOST SDR has a positive effect in reducing air turbulence at the rear of the vehicle. The air flowing over the roof is directed through the JOST SDR diffusor, significantly reducing the drag effect caused by the turbulent air. This creates less air swirl and air resistance and thus results in substantial fuel savings of up to 4%. The initial cost of the SDR roof diffusor is recovered after only a few months.
Besides the remarkable savings on consumption, it also reduces the respective CO2 emissions and protects the environment. Two more benefits of JOST’s SDR roof diffusor resulting from the low air turbulence behind the vehicle are most noticeable during bad weather: The rear of the vehicle remains cleaner and the road view of following vehicles is improved, as less spray mist develops behind the vehicle.
Installing the JOST SDR roof diffuser is very simple. The SDR can easily be installed on the rear frame of a truck body, trailer or semi-trailer. Of course, retro fit installation is also possible. After installation, the SDR roof diffuser is completely maintenance free. The press release does not mention the hight of the device, and that could be tricky. Most modern trailers are four metres high, at least at the front so the hight is critical in most cases.