The Influence of Fuel Management on Unburnt Hydrocarbon Emissions During the ECE 15 and US FTP Drive Cycles

Unburnt hydrocarbon (uHC) emission levels, from three vehicles driving the ECE 15 and US FTP75 test cycles, have been measured on a crankangle timescale. High levels of uHC emissions have been linked to particular drive-cycle features and can be explained by features of the engine management strategy. The data highlight the need to pay close attention to the fuelling of every cycle if large excursions in uHC levels are to be avoided.