The Use of Liquefied Petroleum Gas, Methanol and Unleaded Gasoline in a Turbocharged Spark-Ignition Engine Operating on the Simulated ECE-15 Urban Cycle

Experimental results are presented from engine tests carried out under steady-state conditions, to evaluate the ECE-15 exhaust emission levels of oxides of nitrogen, unburnt hydrocarbons and carbon monoxide for various fuels.

Liquefied petroleum gas, pure methanol and an octane-augmented lead-free gasoline were used, together with a four-star premium leaded gasoline for fuelling both naturally-aspirated and turbocharged versions of a 2 litre overhead-cam, 4-stroke, spark-ignition engine. Test conditions were those designed to simulate the ECE-15 urban driving cycle for engine test-bed operation using a hydraulic dynamometer.

Results show that both liquefied petroleum gas and methanol gave emissions below the ECE-15 limit with the turbocharged engine. The lowest fuel consumption was achieved with the turbocharged engine fuelled with liquefied petroleum gas. Operation of this engine with methanol gave the highest fuel consumption but the lowest exhaust emissions and widest range of stable operating conditions.