Influence of Ignition Timing on the Exhaust Emissions of a Ford Escort Fuelled by Various Ethanol and Petrol Mixtures

The influence of the ignition timing on the exhaust emissions of an old technology vehicle fuelled by various ethanol/petrol mixtures was investigated. All tests were carried out on a 1300cc Ford Escort equipped with a carburettor and without a catalytic converter. The reference petrol fuel E0 and the blends E10, E20 and E50 were used, at three different constant speeds of 30, 50 and 90 km/h, under full load with wide open throttle while the vehicle was on a chassis dynamometer. All measurements were taken at three different settings of the advance angle, at 0°, 4° and 12° BTDC. With the use of an exhaust gas analyser, the concentrations of CO, CO₂, HC, O₂ and NO_X in the exhaust gases at the tailpipe were recorded. For the evaluation of the results the lambda value was calculated from the available recorded data. Changing the ignition timing, while using the blends E10, E20 and E50, had the same effects on the emissions as the reference fuel E0. By advancing the ignition timing, an increase of HC and NOx emissions were measured, while no particular trends were observed in the CO and CO₂ emissions.