# The Indicator of GDI Engine Operating Mode and Its Influence on Eco-Driving
## 4 The Experiment  
The experiment aimed to examine how the information provided by the indicator, which informs about the operational mode of GDI engine run mounted on the vehicle dashboard, affected by the driver behaviour, can significantly contribute to eco-driving. The experiment consisted of eight tests with and without access to the information from the indicator. The tests were carried out on the same road and at a distance of 82.5 km (Figure 4). The distance was covered in two parts, travelled at the same time of each day. The amateur driver (woman), of good consciousness of the environmental threats with minimal technical knowledge, was engaged for the experiment. Only one driver tested the car to minimise the influence of drivers' habits and ensure that a change in the driver's behaviour was due to the response to information from the indicator. The driver was informed about phenomena connected with each operating mode of the GDI engine run and its ecological consequence. The investigation was carried out on a Mitsubishi Carisma  
Figure 3: Photos of the electronic indicator unit (**a**) and the location of the LED on the driver’s panel (**b**). Figure 2: Schematic diagram of the indicator circuit. with a GDI engine (\(V\) = 1843 cm\({}^{3}\), \(Ne\) = 90 kW at \(n\) = 5500 rpm, \(T\) = 174 Nm at \(n\) = 3600 rpm, EURO3). The factory car dashboard provides no information about the economy of driving, which could influence the experiment. The car was equipped with an additional indicator of the operating engine mode. The indicator works by comparing the phase of the injection pulse phase with the ignition pulse for the same engine cylinder. It informs the driver using a three-colour LED, as described in Section 2. The driving test took place in conditions as close as possible to the daily routine use of the vehicle. The road and the times of the day in which the experiment was carried out resulted from the daily need to cover the distance by the driver and the passenger. In the morning, the passenger was taken to the exact same place (point P\({}_{1}\)) and picked up from there in the afternoon. Thus, the test was carried out regularly in the morning (approximately 46.1 km--shown in green) and in the afternoon (about 36.4 km--shown in red). In the morning, the route led from the starting point (S on the map in Figure 2) through the shortstop (P\({}_{1}\) on the map) to point P\({}_{2}\). The route from point P\({}_{2}\) to the stopping point (S--on the map) was covered in the afternoon. To confine the weather influence on fuel consumption, only those runs in similar conditions were selected, namely, dry road surface, similar air temperature, and no strong wind. A similar time of day for all tests ensured similar traffic congestion. The tyre pressure was kept at a constant level. The experiment consisted of 18 road tests and was divided into two parts. For the tests, nos. 1-9, the driver had no access to the information from the indicator (it was covered) but had access for the subsequent nine tests (tests no. 10-18). In both cases, the driver tried to drive at the optimum speed for the traffic conditions on the road. During the tests, the signal from the accelerator pedal was not recorded. The driver intuitively adjusted the method of pressing the pedal to make driving as economical as possible. Using the indicator (tests 10-18), the driver aimed at maximising the lighting time of the indicator LED in green. Although the accelerator pedal method affects the fuel consumption, in this case, the experiment was focused on the effects of the driver activity, which is complex and involves other activities, such as shifting gears and pressing the clutch and/or brake pedal. Thus, the measurements were limited to the parameters resulting from the driver's actions. In particular, data allowing the analysis of the fuel injection system operation, with specific emphasis on the registration of the time of the engine run in each analysed mode, were collected.