Fuels — typical calorific value range of petrol (gasoline) Select the closest standard range for the lower heating value of petrol used in spark-ignition engines.

Introduction / Context:The calorific value (lower heating value, LHV) of petrol (gasoline) is a key parameter in fuel economy, engine calibration, and emissions modeling. Knowing its typical range helps in quick engineering estimates and comparison with other fuels such as diesel, CNG, and ethanol blends.

Given Data / Assumptions:

• Petrol composition is hydrocarbon-based with small additives.
• Values refer to LHV at standard conditions, per kilogram of fuel.
• Blending variations exist, but common exam ranges are expected.

Concept / Approach:Typical LHV of petrol is about 43 MJ/kg, with a narrow range around this mean. This arises from the hydrocarbon mix (C5–C12). Diesel tends to be similar or slightly higher depending on cut and composition. Ethanol content can reduce LHV of blends proportionally to blend fraction.

Step-by-Step Solution:

Verification / Alternative check:Engineering handbooks and thermochemical tables report gasoline LHV close to 42–44 MJ/kg; mid-43 MJ/kg is a common design value.

Why Other Options Are Wrong:

• 36.5 – 38.5 MJ/kg: too low; closer to some alcohol fuels.
• 39.4 – 42.5 MJ/kg: lower than typical modern petrol.
• 45.5 – 47.0 MJ/kg and 50 – 52 MJ/kg: too high; those approach diesel higher-end HHV or kerosene claims, not petrol LHV.

Common Pitfalls:Mixing up higher heating value (includes condensation heat of water) with lower heating value; not accounting for ethanol blending which reduces LHV.

Final Answer: