It is a generally accepted fact that the advantage of diesel engines over their gasoline-powered counterparts is superior fuel consumption. However, attempts to use diesel engines as car powerplants have been hampered by the associated increase in toxic emissions. Research was carried out with the objectives of achieving the lowest fuel consumption for a diesel-powered passenger vehicle in the 1,590kg equivalent inertia weight class while also meeting the 2005 European diesel exhaust emissions standards (EURO IV).
This paper starts with a description of the experiments on combustion and the results of the simulations and experiments using a visualization apparatus, followed by a description of the fuel consumption, emissions and power performance of the engine when fitted in an actual vehicle.
To begin with, the relationship between engine displacement and fuel consumption was investigated. The result shows that the larger the displacement is, the lower the fuel consumption becomes if the same emissions characteristics and driving performance are maintained by adjusting injection and combustion system parameters and gear ratios.
In the next step, a study was performed to identify the optimum combustion method that would result in an improvement in brake specific fuel consumption (BSFC) and a significant reduction in exhaust emissions, when compared to a modern European diesel engine, while at the same time not compromising combustion noise.
The results of the study reveal that it was possible to achieve significant reductions in BSFC, engine-out NOX and particulate emissions, compared to the results achieved with a modern European diesel engine, while at the same time being able to maintain combustion noise at a low level. These measures, adopted in conjunction with the De-NOX catalyst, contribute greatly to meeting the 2005 European emissions standards while also achieving a low fuel consumption of 5.4 liters/100km despite a vehicle weight of 1,590kg.