Fuels — Approximate specific gravity of petrol (gasoline) At standard reference conditions used in automotive practice, what is a typical specific gravity value for petrol?

Introduction / Context:Specific gravity (relative density) indicates a liquid’s density relative to water at a reference temperature. For gasoline, this affects fuel system calibration, evaporative behavior, and mass-based fuel economy calculations.

Given Data / Assumptions:

• Automotive petrol at around 15 °C reference conditions.
• Typical commercial blends (not aviation gasoline or special racing fuels).

Concept / Approach:Common gasoline blends have specific gravity roughly in the 0.70–0.77 range at 15 °C. A nominal textbook value of about 0.74–0.75 is often used for engineering estimates where precise density is not provided.

Step-by-Step Solution:Recognize typical range for petrol density.Select a representative value used in calculations.Answer: approximately 0.75.

Verification / Alternative check:Fuel data sheets from refineries show densities corresponding to specific gravities in the cited range depending on aromatics and temperature.

Why Other Options Are Wrong:0.85/0.95/1.25: too high for petrol; closer to diesel or heavier oils.0.60: too low for any standard road gasoline.

Common Pitfalls:Confusing gasoline with diesel (SG ~0.82–0.86).

Final Answer:0.75