The Mayor of Sao Paulo, Gilberto Kassab, has presented a new hybrid bus model, which will be tested in two phases: the first will happen until the beginning of November 2010 and the second, from March until August 2011, when the bus will be moving around the city. Being developed by Volvo, the vehicle carries to motors: one is moved by biodiesel and the other, by electricity. Both work in parallel or in an independent way. The hybrid system provides a 35% reduction in fuel consumption.

The electric motor from the hybrid bus is used to start the vehicle and accelerate it until a 20 Km/hour speed. This motor also produces energy during the break. The diesel motor, on the other hand, starts working when the vehicle reaches a higher speed.

When the vehicle is not moving, which can happen during traffic jam or when the vehicle stops at a bus stop as well as at a traffic light, the diesel motor is off. Studies made by Volvo shows that the time during which the bus is not in movement can represent until 50% of the total operation period. During all this time, there is no polluting emission, because the diesel motor is off.

The hybrid system provides a 35% reduction in fuel consumption. Regarding the decrease on tailpipe emissions, they vary between 80% and 90%, comparing to diesel conventional motors.