The Nuna4 also won the 2007 World Solar Challenge with an average speed of 90.87 km/h (56.46 mph) ahead of the Belgian Umicore and Australian Aurora teams, making its fourth consecutive win.
Because of risks involved with the high speeds reached by the solar cars in the previous races (Nuna3 averaged over 102 km/h (63 mph)) and tighter speed limits on the Australian roads the rules were changed for the 2007 race to enhance safety and reduce speed.
Its data is transferred via a WiFi connection to a support vehicle.
A computer in the support vehicle calculates the optimum speed based on the data from the car and additional information including wind speed and direction, the gradient of the road, solar conditions and the state of the batteries.
The driver only has to steer whilst driving using this adaptive cruise control system.