Today, about three quarters of all passenger cars on German roads run on petrol - a lot of energy is already being saved with optimized combustion engines. However, alternative engines can be even more efficient and environmentally friendly, depending on the the distance to be covered and the weight of the vehicle. April's edition of VIAVISION gives you an overview of the different types of drives, and shows you the advantages and disadvantages as well as the development potential of the optimized combustion engine, the electric motor, the fuel cell and the hybrid drive. Automotive lightweight construction can also help to make vehicles more efficient and eco-friendly. Also: South America in numbers -- Brasil as the world's second largest ethanol producer.