The Fuel Consumption of Passenger Vehicles - Literature review Example

Utilizing theoretical and experimental methods, a uniform mathematical model arrived at that could be applied to small parts of the overall drive cycle to predict fuel consumption without any need for physical testing.

7.1. Summaries and Conclusions

The primary objectives of this study were to determine engine speed and engine torque. In addition to the primary objectives, a number of different input and output parameters need to be determined to ensure that the engine is operating within safe limits and optimally. Secondary parameters that required determination and control during testing included (but were not limited to):

• Engine torque;
• Engine speed;
• Fuel emissions;
• Fuel consumption;
• Temperatures:
  • Head temperature;
  • Exhaust temperature;
  • Coolant temperature.

A number of other parameters were also monitored to determine additional operation characteristics. These parameters included (but were not limited to):

• Combustion pressure;
• Engine dynamics:
• Acceleration of components;
• Vibration levels;
• Stress is produced in various components.
• Intake pressure;
• Exhaust pressure;
• Engine acoustics;
• Ignition timing;
• Engine knocking;
• Valve lifts.

Measurement of the parameters listed above was done using automated means in order to enhance accuracy (Gitano-Briggs, 2008, p.40). Moreover, this allowed real-time monitoring of equipment to perform adjustments online.

7.2. Review of Aim and Objectives

The primary aim of this research was to examine the fuel consumption of passenger vehicles based on a standardized driving cycle. In addition, this research aimed to explore the development of a mathematical model that could be used to predict the fuel consumption of passenger vehicles. The current research was able to meet its objectives in large part. Laboratory and real-life driving provided significant findings on the fuel consumption of passenger vehicles. A mathematical model was developed based on the NEDC driving cycle that was validated for most testing regimes in the driving cycle. However, the current mathematical model has certain limitations in the NEDC driving cycle and is also limited to other standard driving cycles.

7.3. Suggestions for Future work

The current research provides a mathematical model for validating fuel consumption over the NEDC driving cycle under urban and extra-urban driving conditions. Additionally, laboratory testing of engines was carried out in order to determine operating parameters. Laboratory testing was done through a generator-type dynamometer based on engine torque testing.

The mathematical model was tested against real-life driving data based on the NEDC driving cycle. Data was fitted from real-life driving conditions on the mathematical model. Results from data fitting provided that the mathematical model was fit for certain regimes of the NEDC. The use of small differentials for the NEDC driving cycle under the mathematical model provided better data fit results. It can be inferred that using smaller differentials for the driving cycle provided more accurate results. The mathematical model derived in the current research has not been tested for other driving cycles. Further research is required to validate the current mathematical model for other standard driving cycles such as the CAFE, JC 08, and other allied driving cycles.

In addition to the above, this research highlights the serious shortcomings of a number of standard driving cycles. The NEDC driving cycle was seen as the best option in the available driving cycles but the need for an internationally standardized drive cycle remains. Further research is required to develop standard driving cycles based on the NEDC driving cycle and the driving cycle proposed by the United Nations. An internationally standardized drive cycle would ensure that a simpler mathematical model could be developed and used. Moreover, this would also ensure that a uniform fuel consumption testing system would be available worldwide for testing passenger vehicles.