• Journal of Auto-vehicle Safety Association
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• v.10 no.1
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• pp.45-51
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• 2018

There are some ambiguities of the information on the fuel economy provided to the consumers because the standard and the detailed regulations for the fuel economy of the two-wheeled vehicle have not been established in Korea. Since Korea has been a signatory of World Forum for Harmonization of Vehicle Regulations since 1998, it is possible to remove the ambiguities by adopting the WMTC (Worldwide-harmonized Motorcycle Test Cycle) measurement method for the fuel economy of the two-wheel vehicle. As a preliminary study on the WMTC mode fuel economy, road loads measured by coast down method and table method were compared for the two types of two-wheeled motorcycles on sales in domestic market. In the same model, it was confirmed that the deviation of WMTC mode fuel efficiency was below -5% between products. On the other hand, the difference of WMTC fuel economy exceeded 5% between the coast down method and table method.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.34-39
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• 2013

The gear shifting timing of a manual transmission vehicle is influencing fuel economy. This paper focuses on an gear shifting indicator of an city bus with manual transmission, which can improve fuel economy. The shift indicator is supposed to collect the vehicle data during driving, calculate and compare fuel economy with and without gear shifting, and indicate the proper gear shifting timing. The H/W and S/W of the shift indicator are developed and tested on city bus in this research. The experiments are carried out on real road by 3 different drivers and the results show the improvement of fuel economy from 6.0% to 21.4%. The average engine torque and speed are reduced due to early gear shifting and the usage of highest gear is increased. The results of chassis test are also performed and show 7.5% improvement of fuel economy.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.4
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• pp.103-108
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• 2012

Fuel economy is an important factor in a vehicle owing to recent energy supply and environmental problems. This paper deals with fuel cell hybrid vehicles (FCHVs) and introduces a fuel economy evaluation method. The fuel economy of an FCHV depends on its power management strategy. Two rule-based power management strategies are applied to this paper and their fuel economy is evaluated based on the optimal control theory. The concept of the optimal line is also applied to this paper, which is used to compare the fuel consumption of a power management strategy to the optimal result. The two rule-based strategies are also compared to each other.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.60-67
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• 2006

To improve the vehicle fuel economy, various technologies have been studied. Meanwhile it deteriorates fuel economy that the increased driving torque for Power Steering System (PSS) due to weighted vehicle and widened tire for low speed driving and parking. So the larger driving torque for PSS is, the lower fuel economy is. Therefore, the study about the effect of the driving torque for PSS and the engine total friction must be preceded to improve the vehicle fuel economy. In this study, a PSS module separated from the vehicle is used to measure the driving torque for PSS with respect to the pressure of PSS. The result shows that the driving torque for PSS was in direct proportion to the pressure of PSS 3 (N-m) driving torque for PSS vs. 10 (bar) pressure of PSS, and 8 (N-m) vs. 40 (bar). In addition, the driving torque and pressure for PSS was measured according to the engine speed in the component test condition which was in the vehicle condition. Measuring the driving torque for PSP in the vehicle condition was established by using the VeFAS which was a fuel economy analyzer developed in our lab and installing PSS By-pass line. The effect of the driving torque for PSS on the vehicle fuel economy was analyzed with FTP-75 cold start mode.

• Journal of Institute of Convergence Technology
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• v.4 no.1
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• pp.9-13
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• 2014

The purpose of this study is analysis to vehicle's fuel economy and emission gas characteristics by fuel type. The test vehicle were selected to similar weight and performance, the test vehicle was used three representative mode(CVS-75, HWFET and NEDC) in order to evaluation fuel economy and emission gas. For reference, environment pollution cost was calculated on the basis of the exhaust emissions occurred in the test in progress.

• International Journal of Automotive Technology
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• v.6 no.3
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• pp.269-275
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• 2005

The engine cooling system for a medium duty V6, 4.5 L diesel engine was modeled with a commercial code, GT-Cool in order to investigate the effect of controllable electric pump on the cooling performance and the fuel economy. The simulation results of the cooling system model with mechanical coolant pump were validated with experimental data. Two different types of electric pumps were implemented into the cooling system model and PID control for electric pump operation was incorporated into the simulation study. Based on the simulation result with electric pump, conventional thermostat hysteresis was modified to reduce pump operation for additional improvement of fuel economy, and then the benefit of electric pumps with modified thermostat hysteresis on fuel economy was demonstrated with the simulation. The predicted result indicates that the cooling system with electric pump and modified thermostat hysteresis can reduce pump power consumption by more than $99\%$ during the FTP 74 driving cycle.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.370-373
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• 2005

In this research, we presented the regenerative braking algorithms considering fuel economy and charging oftenness, and also analyzed these algorithms. The first algorithm was the regenerative braking algorithm for the ideal recovery of kinetic energy. The HEV using this algorithm had high fuel economy, on the other hand frequent charging was occurred. The second algorithm was the regenerative braking algorithm for reduction of the charging oftenness. Using this algorithm, the HEV had the low charging oftenness and small loss of fuel economy.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.181-185
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• 2006

A study to get better vehicle fuel economy is described based on an express bus. The approach is based on using a commercial software vehicle simulation to identify the relative efficiency of each of the vehicle systems, such as the engine hardware, engine software calibration, transmission, cooling system and ancillary drives. The simulation-based approach offers a detailed understanding of which vehicle systems are underperforming and by how much the vehicle fuel economy can be improved if those systems are brought up to best-in-class performance. In this way, the optimum vehicle fuel economy can be provided to the vehicle customer. A further benefit is that the simulation requires only a minimum of vehicle testing for initial validation, with all subsequent field test cycles performed in software, thereby reducing development time and cost for the manufacturer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.2925-2930
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• 2011

A vehicle fuel economy is very important issue in the view of fuel cost and environmental regulation. The fuel economy is much improved according to the development of electric, electronic and mechanical technology, but up to now the measurement of it tests the given mode(LA-4, FTP-75, etc) within computer simulation program and engine dynamometer. This fuel economy is different with it of real road. The one of main reason is not considered the gradient of the road. To estimate the effects of fuel economy at highway with gradient in this paper, we measure the amount of fuel consumption and calculate the fuel economy of it with running the Youngdong highway with high gradient. Also this paper analysis and compares the fuel economy with gradient and without gradient when the vehicle runs the same driveway. Then we calculate the total energy created the difference of fuel consumption amount of the two cases and calculate the consumpted energy by tire driving force from the torque and power of engine in the simulation. This paper verifies the relation of the driving force and the total energy by creating the difference of fuel consumption amount. This paper also proposes the method of fuel economy improvement despite of gradient at the result.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.115-120
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• 2010

The reduction rate of fuel consumption by showing the fuel injection data for driver was measured in this study. The fuel injection data are composed of injection period, real time fuel economy and average fuel economy. The fuel consumption was measured by processing the voltage signal of injector and driven distance by GPS sensor. The fuel consumption was reduced by driving more carefully, i.e driving more steady without sudden acceleration and deceleration watching these fuel injection data. The reduction rate was up to 37% and the rate increased as the driver is customed to this driving pattern.