The share of medium and large vehicles, accounting for 5% of the total. However, it is estimated to occupy that the ratio of greenhouse gas emissions of those is about 36% of the total. Therefore, medium and large vehicles, including buses improve fuel efficiency is needed for the study. Meanwhile, using eco-friendly driving techniques of improving the fuel efficiency of vehicles has been steadily. But the study was mainly focussed on passenger cars, there has been little consideration for commercial vehicles by weight and energy consumption characteristics of different patterns.
In this paper, it is expected that the effect of change the driving pattern on fuel economy based on velocity, acceleration, gear shifting for diesel city buses. The heavy weighted city bus enjoy high efficiency at the area of low engine speed and high load. The main factor of fuel economy are velocity drop, to soften acceleration and early gear shifting. ECE driving cycle are selected to develop driving profiles for the factors, and the profile development methodology can be tested repeatedly.
According to the simulation, the effect of change the driving pattern is as follows. In the case of 10% reduction of velocity, it is predicted 20.9% effect on fuel economy. However, the driving time is extended about 8.4%. In the time interval over acceleration 0.5[m/s2], it enjoyed 8.5% effect on fuel economy and the driving time is extended 1.5% comparing with Seoul City Bus Real road Driving profile, so we called CBRD. In the case of early gear shifting 3 seconds, it is predicted 5.1% fuel effect. The simulation results that the velocity and acceleration are up and down on fuel economy. On the other hand, the early gear shifting has the power of improvement additional fuel economy.
The early gear shifting is believed to be the first factor of driving patterns change when considering all the contributions, driving time, mileage, fuel efficiency. In addition to that, acceleration of relaxation has worth the investment. Finally, the change of velocity is recommended with time to spare.
