Fuel Injectors & Pumps – Section 4.3 Fuel Cetane Number

Section 4.3
Fuel Cetane Number

The cetane number affects the time delay between the beginning of fuel injection and the start of combustion. In a cold engine, a low cetane number of below 40 causes hard starting, visible white smoke, poor fuel economy, and lack of power in cold ambient temperatures, until the engine warms up. In engines with charge air-cooling, a low cetane number fuel may also cause white exhaust smoke during light load operation.‪

The minimum cetane number specified for Detroit Diesel engines is 45. The primary benefits of a high cetane number are improved starting and smooth running when the engine is cold. The higher the cetane number of a diesel fuel, the shorter the lag time from when the fuel first enters the combustion chamber until it ignites. Diesel fuel with a cetane number above 45 will provide increased power and economy.‪