In trials, the new technology has delivered average cost savings on fuel of around 6%, as well as a similar percentage reduction in CO2 emissions.

Ian MacAulay, UK fleet engineering services, DHL Supply Chain, said: 'New developments such as Jetpia are making a big difference to the carbon output of our fleet and are helping us move towards our target of improving the CO2 efficiency of our own operations and those of our subcontractors by 30% by the year 2020.

'In combination with other initiatives such as driver training, the implementation of "loose loading" to increase vehicle capacity and aerodynamic solutions such as teardrop trucks and trailers, we are always aiming to deliver the most cost and carbon effective fleet solutions for our customers.'

The air dynamics technology, developed by Jetpia in South Korea, fits to the end of the exhaust and uses the venturi tube principle to prevent the back stream of air and "dirty exhaust gases" from flowing back into the engine via the exhaust. In so doing, the engine no longer has to process these impurities and as a result runs more efficiently.

Jetpia’s European development director, Matt Vickers said: 'Due to its customer focus, continuing developments of the company’s "GoGreen" policies and the scale of their fleet, we were pleased DHL were the first to trial this new technology outside of Asia.'