The last few years have seen some satellite navigation systems go from advising motorists of the fastest routes to recommending more fuel-efficient trips. Now Bosch, in Germany, has developed a route-planning system that could squeeze even more fuel savings from a journey by taking into account the car’s weight, aerodynamics, engine size, transmission, and even driver aggression level. Bosch says its new ECO2 satnav software can reduce fuel consumption by 9 percent on average while increasing average journey time by only 9 percent.
The fuel-efficient routes plotted by existing satnav systems, including some TomTom and Garmin devices, are calculated according to the speed limits of particular roads and the number and type of intersections along a journey. But the route may not be the same for all vehicles and drivers, according to Stefan Meyer of Robert Bosch Car Multimedia, a division of Bosch based in Hildesheim, Germany. For example, some vehicles are more efficient at accelerating than others. Likewise, a route that might be fuel-efficient for a more cautious driver may be less so for one who prefers to drive faster–depending on the car’s most fuel-efficient speed.
With the ECO2 software, a driver can select a driving style: fast, normal, or economical. An algorithm factors this into its calculation of the most economical route for the chosen driving style.
ECO2 is designed to connect to a car’s central computer to access specific details, such as engine size, type of fuel and transmission, and air and roll resistance (how much drag the tires produce and how the car handles in turns). From this, ECO2 determines “speed-dependent fuel consumption curves”–how much fuel the vehicle will consume under different driving and road conditions. “So when going from A to B, the algorithm will calculate all the little distances in a route with the least total fuel consumption,” says Meyer.
This doesn’t guarantee that the driver won’t hit any subsequent traffic, says Meyer. ECO2 is designed to be used integrated with satnav systems, but it could also be used in a standalone device that connects to separate satnav equipment.