Fuel Effects on Combustion and Emissions in a Direct Injection Diesel Engine

The emissions and performance of five diesel fuels, covering a range of cetane numbers and volatilities, were evaluated at three speeds and equivalence ratios in a single-cylinder, DI diesel engine. Graphical comparisons and regression analysis of the data revealed that cetane number and to a lesser extent volatility are the fuel parameters that most strongly influence emissions and performance, with higher cetane number and higher volatility fuels providing the best performance and lowest emissions. Trends toward lower cetane number, lower volatility fuels must be reversed to meet the emissions and performance standards of future light-duty DI diesel engines, should such engines be developed for use in automotive applications.