The Cayman models are already designed to operate on fuels with an ethanol content of up to 10%. Ethanol has a positive impact on the CO2 balance since the plants cultivated for the production of this biofuel also absorb CO2 from the atmosphere.

The active carbon filter and a special coating on the fuel tank reduce the amount of hydrocarbons released from the fuel system. All fuel lines are made of aluminium, while vapour-carrying lines are made from multi-layered plastic.