Question

______ is the presentation of the anti-knock value of diesel fuel.
1. Cetane number
2. Diesel constant
3. Octane number
4. Fuel number

Answer 1

Correct Answer - Option 1 : Cetane number

Explanation:

Cetane rating, also known as cetane number is a measurement of the quality or performance of diesel fuel.

• The higher the number, the better the fuel burns within the engine of a vehicle.
• The cetane number is similar to the Octane Rating in that it is a rating assigned to fuel to rate the quality of its combustion.
• The main difference between cetane and octane ratings is that the octane rating represents how well a fuel can resist pre-ignition due to compression ensuring the fuel ignites only from a spark from the spark plug.
• However, the cetane number measures the delay in the ignition time of the fuel. 
• A higher cetane number resulting in quicker ignition of the fuel leads to less non-ignited fuels building up inside the combustion chamber, as well as more complete fuel combustion.
• Better fuel combustion and quick ignition lead to quicker starting for vehicles, as well as an engine that operates more quietly as only misted fuel is ignited and build-up inside the engine is minimized.
• Moreover, fuel efficiency improves with more complete combustion and harmful emissions are reduced.