Among statements about aromatics, specific gravity, and gross calorific value (GCV) trends for petrofuels, identify the single incorrect statement by comparing density–GCV relations on weight and volume bases.

Introduction / Context:
Fuel property trends link composition, density, and heating value. Understanding how specific gravity correlates with GCV on both mass (kcal/kg) and volume (kcal/litre) bases helps avoid common misconceptions when comparing fuels of different cut ranges.

Given Data / Assumptions:

• ρ denotes specific gravity at 15.5°C.
• Comparison across typical refinery fuels (naphtha → diesel → heavy fractions).
• Generalized empirical correlations capture GCV dependence on ρ.

Concept / Approach:
As fuels get heavier (higher ρ), their hydrogen content usually decreases (higher C/H), so GCV per kilogram tends to drop slightly. However, per litre, heavier fuels can deliver similar or greater energy because density is higher. Therefore, “heavier gives higher GCV per kg but lower per litre” is reversed from the typical trend and is the incorrect statement here.

Step-by-Step Solution:

Verification / Alternative check:
Standard refinery property tables and correlations indicate declining mass-based GCV with increasing density and often stable/higher volume-based GCV for heavier cuts.

Why Other Options Are Wrong (i.e., not the incorrect one):

Common Pitfalls:
Confusing mass-based with volume-based comparisons; always specify the basis for calorific value.

Final Answer:
Heavier petrofuels have higher GCV on a weight basis but lower GCV on a volume basis.