Abstract
The main objective of the reported work was to develop a methodology to assess the fuel consumption and the efficiency of the propulsion system of passenger cars equipped with internal combustion engines in road tests carried out to compare the performance of fuels with different formulations. The examination has been done out in highway travels. A Peugeot 407 HDI station wagon, with a 2,0 liter engine, has been equipped with different measurement systems. The measurement equipment is based upon two vehicle data loggers. A real-time fuel consumption metering system is combined with a GPS logger in order to analyze trip fuel consumption with different conditions in speed and altitude. An OBD II data logger is also mounted and the analog outputs of two pressure sensor are also connected to it. OBD II provides the vehicle and engine information available at the CPU unit, while the pressure sensors are connected to three pressure taps placed on the front of the vehicle to provide information about the relative velocity between the car and the air and the flow angularity. In the test, the impacts of speed, acceleration, road slope and wind disturbance on fuel consumption were analyzed for different fuel formulations. The developed system revealed to be well adapted to the requirements of the research project, allowing an accurate measurement of the fuel consumption and all the relevant parameters related to the vehicle movement. The best compromise in terms of sampling parameters has been achieved with a data acquisition frequency of 10 Hz, being the values decimated to 1 Hz, with the exception of the fuel consumption that is analyzed for 10 s integration intervals.
KEYWORDS On-road tests; performance of IC engines; fuel consumption