Which crude oil fraction is matched correctly with its typical use?

• A. Gasoline — petrol.
• B. Petrol — used as domestic heating fuel.
• C. Lubricating oil — used as a car fuel.
• D. Diesel — fuel for heavy vehicles such as trucks and buses.

Answer: (D)

The concept being tested is how crude oil is separated into fractions with different properties and typical uses. In fractional distillation, crude oil is heated and split into fractions that boil away at different temperatures. Lighter fractions are used for fuels in light engines, while heavier fractions are suited to fuels and other products with different viscosity and energy needs. The diesel fraction is heavier than gasoline and is refined specifically for diesel engines, which are common in heavy vehicles like trucks and buses. That makes diesel the standard fuel for these vehicles. Gasoline (petrol) is the lighter fraction used mainly in cars, not domestic heating, and lubricating oil is used for lubrication rather than as a fuel. Therefore, the correct match is diesel as fuel for heavy vehicles.