Quad-fuel taxi unleashed in Uruguay

© Municipality of MontevideoA regular Siena on the outside, the Tetrafuel hides CNG tanks inside the trunk

The car, which is a modified Fiat Siena, can be powered with any of the following: petrol, ethanol, gasohol (gasoline and alcohol mixture) and natural gas. It was first presented in September as part of a project aimed at using domestically produced energy. Savings are expected to achieve a 40% level compared to conventional fuels. The Siena Tetrafuel, as it is called, will now enter a 90-day-long test run to help evaluate the technology in everyday driving conditions.

The Tetrafuel technology isn't actually new as Fiat has been offering quad-fuel Sienas since 2008 (mainly in Brazil). The engine is said to "prioritise” the use of CNG to reduce costs and emissions, which means it isn't entirely for the driver to decide which fuel to use at a given moment. The ECU continuously monitors driving conditions (based on engine load data) and selects the most appropriate fuel in real time, with CNG being given a priority. Switching between fuels is said to be seamless and range in the CNG mode is 244 km, with tanks fitted into the car's trunk.

Alternative fuels for the Fiat Siena Tetrafuel are supplied by local providers. For example, CNG will come from an LNG regasification plant in Puntas de Sayago, near Montevideo. The plant is currently under construction and will be launched in March, 2015. Ethanol, on the other hand, is going to be provided by ALUR – Alcoholes del Uruguay, a domestic alcohol producer. We keep our fingers crossed for the car's tests to live up to and exceed expectations!