Fuel consumption, exhaust and noise emissions are to a large extent influenced by the driver's behaviour, especially in cars with manual transmission in urban traffic. The driver does not act independently of surrounding traffic and the vehicle, but is connected with those by numerous interactions. To find out whether the driver's behaviour can be influenced by the vehicle's layout, variations of final drive ratio - ranging from extreme over-drive-type to sport-type layout - and the relation between accelerator pedal input of the driver and the vehicle's torque response were examined. By those components of the vehicle the driver defines the engine operating conditions, engine speed load. The investigations were carried out in Darmstadt city traffic with several drivers. The effects of vehicle variations on engine operating parameters were relatively small, since the driver partly compensates for these variations by adapting gear choice or accelerator pedal position. Fuel consumption (excluding standstill) of three drivers varied by about 4% for the investigated final drive ratios and by about 7% for accelerator pedal layouts. All results were compared with investigations on the surrounding influences - personal drive style and traffic density. These two also have significant impact on fuel consumption, with a range of 22% for the individual drive style of 20 drivers and about 30% for traffic density.
Abstract