An experimental investigation was conducted into the effect of fuel sensitivity on combustion and emissions of partially premixed combustion on a modified single-cylinder testing engine fueled with different fuels of the same research octane number(RON) but different sensitivities. The fuels used were toluene reference fuels of different sensitivities of 0

2

5

8 and 11(with 11 the greatest)

and a market gasoline with the RON of 92. The results indicate that with a fuel of higher sensitivity

the ignition delay is longer

the fuel/air mixture more homogeneous

and the premixed combustion stronger with more NOx. With the increase in fuel sensitivity

the CA50 first delays and then advances

resulting in the most delay of CA50 with the fuel having the sensitivity of 2. With a fuel of lower sensitivity

the rate of maximum pressure rise is smaller; but the rate of maximum pressure rise with the gasoline is the highest due to its stronger volatility and more premixed combustion. Moreover

with the fuel having the sensitivity of 2

the engine has the most heat release near top dead center

resulting in the highest thermal efficiency. With the gasoline and the fuels having the sensitivities of 5 and 8

engine soot is the lowest. The sensitivity of the gasoline with the RON of 92 is between 5 and 8.