Fiat specialise in making small cars and so have rarely been questioned on their environmental credentials. Perhaps that's why their efforts in this space remain largely conceptual.
Fiat have concept cars that run on methane and hydrogen and has brought out the dual fuel methane/petrol Natural Power range which bizarrely includes some of the highest emission vehicles in the Fiat fleet.
2006 European Performance Sales weighted CO2 average : 144g Share in carbon emissions : 6.84% * Share in vehicle sales : 7.58% - 1 088 000
* based on all new cars being driven an equal distance