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.
Other satnav makers are already focusing more on fuel economy. Econav, which is unconnected with Bosch’s product, was launched last year by the Spanish company Vexia, based in Madrid, Spain. It asks users to specify their car type and number of passengers so it can better gauge when a driver should change gear or reduce acceleration.
David Elder, U.K. country manager for Vexia, is skeptical that the information collected by Bosch’s software will make much difference. “I would think the optimum route would be the same for whatever vehicle you are driving,” he says.
This may be true for short journeys, says Meyer, but the system will suggest different routes for longer trips. According to Meyer, ECO2 will go into production this summer and will be integrated into the dashboard navigation systems of a number of cars, but he would not specify which makes or models.
John Holland, CEO of Journey Dynamics, a traffic technology company based in Guildford, U.K., says that avoiding traffic will affect fuel consumption more dramatically because a continuously moving vehicle does not accelerate as much as a vehicle in stop-and-go traffic. But by far, says Holland, the biggest influence on fuel consumption is driver behavior. Giving a driver feedback when they are overaccelerating can markedly influence the amount of fuel they use, he notes. Meyer agrees that driver behavior is a major factor, and says Bosch is working on this too.
Holland also believes that the 9 percent increase in journey time is unnecessary. “There’s good evidence that driving economically doesn’t necessarily mean a longer journey time. It doesn’t mean having to drive like a granny at 40 miles per hour down the motorway.”