Transportes Urbanos de Sevilla – TUSSAM, used to operate a fleet of 237 Euro III and Euro IV diesel buses.
They were classified into 12 meters (150 vehicles) and articulated (87 vehicles); the most representative brands being Renault, Iveco, Man and Scania. In March 2011, after obtaining favourable results in fuel efficiency (first test carried out in 2010 with four buses), XBEE Enzyme Fuel Technology started to be used in B15 biodiesel fuel for the entire fleet.
A reduction in consumption of -1.78% in 12-meter vehicles and -0.97% in articulated buses was verified, comparing the data for the period March 2011 – April 2012 with the average of the two previous years 2009 and 2010.