Mercedes-Benz engineers have developed three vehicles based on the so-called sandwich floor architecture. This is possible thanks to Concept BlueZERO and the integrated technologies F-CELL, E-CELL and E-CELL PLUS. The F-CELL runs on a fuel-cell drive that is already used in a low-volume production version of the B-Class. A chemical reaction between hydrogen and oxygen enables the drive system to generate electrical energy – without using fossil fuels. The second drive concept (E-CELL) operates with an innovative 120 V lithium-ion battery. The third BlueZERO unit is called E-CELL PLUS. In this case, a 1.0 litre turbo petrol engine in the rear of the vehicle is installed to drive the power generator. The three-cylinder engine re-charges the lithium-ion battery when required. On this basis, the vehicle can cover up to 600 km on a single tank of fuel – and 100 km without a petrol engine. A further advantage of these drive systems is the fact that maximum torque is available as soon as the vehicle moves off, which ensures excellent acceleration.