Analysis of fuel consumption of a spark ignition engine in the conditions of a variable load

Abstract

This paper reports the results of a study into operating parameters of an system consisting of an SI engine and a driver train in a Fiat Panda passenger car in the conditions of a variable load. The analysis was primarily concerned with the variability of fuel consumption resulting of the changing load applied to the driving wheels in the conditions of a test performed on dynamometer rollers. The bench test included a dedicated driving cycle in which a constant linear speed of the car was changed every 10 km/h and subsequently maintained for registration and analysis purposes. The focus of the study involved the identification of the points characterized with the minimum specific fuel consumption. Throughout the test, the load applied to the transmission was alternated by simulating an increase of road inclination for which the variability of the engine efficiency was analyzed.