CDX 182A final exam

During the last few years, emissions from heavy-duty diesel trucks and buses have: - ANSWER-been significantly reduced. Down speeding is: - ANSWER-downshifting a transmission to increase engine speed. upshifting a transmission to decrease engine speed. using low axle gear ratios to reduce engine speed. Technician A says that diesel engines supply only enough air to completely burn all the fuel in the combustion chamber. Technician B says that diesel engines supply excess air to the combustion chamber to completely burn all the fuel in the combustion chamber. Who is correct? - ANSWER-Tech A Both Techs Neither Techs Carbon dioxide is: - ANSWER-regulated by fuel economy standards. What type of ignition system does a diesel engine use to ignite fuel? - ANSWER-Compression Which tires tend to lift during torque reaction on a heavily loaded diesel engine? - ANSWER-Left front and right rear Technician A says that diesel engines use longer stokes than SI engines. Technician B says that SI engines use longer strokes than diesel engines. Who is correct? - ANSWER-Technician A Technician A says that high crevice volume in a diesel engine is responsible for producing excessive amounts of particulate emissions. Technician B says that high crevice volume produces excessive amounts of NOx emissions. Who is correct? - ANSWER-Neither Technician A nor Technician B In which of the following categories of emissions do crankcase emissions belong? - ANSWER-Particulates Technician A says that a diesel's high torque output is due to its slow speed characteristics and short crankshaft throws. Technician B says that a diesel's high torque output is created when more air and fuel are added to the cylinder. Who is correct? - ANSWER-Tech A