Technician A says that diesel fuel in a vehicle tank can degrade when exposed to high temperatures. Technician B says that the most volatile fractions in a diesel fuel are the ones that define the CN of the fuel. Who is correct?

Question

Quizplus · Accepted Answer

Diesel fuel is a complex mixture of hydrocarbons, and the most volatile fractions are the ones that define the cetane number (CN) of the fuel. CN is a measure of the ignition quality of diesel fuel, and it is important for ensuring that the fuel burns properly in the engine. When diesel fuel is exposed to high temperatures, the more volatile fractions can evaporate, which can lead to a decrease in CN. This can make the fuel more difficult to ignite, and it can also lead to engine problems.

Technician a Says That Diesel Fuel in a Vehicle Tank