Diesel vs Petrol (Gasoline) Density: Fuel Comparison Guide
Chemical chain length differences, energy density per litre, EN 590 vs EN 228 standards, and fuel economy impacts.
Automotive Diesel (EN 590)
Composed of longer hydrocarbon chains (C₁₀–C₂₂), providing higher volumetric energy density.
Unleaded Petrol / Gasoline (EN 228)
Composed of shorter hydrocarbon chains (C₄–C₁₂), more volatile with lower density.
Direct Mathematical Comparison
| Parameter | Diesel Fuel (EN 590) | Petrol / Gasoline (EN 228) | Difference |
|---|---|---|---|
| Standard Density @ 15°C | 0.832 kg/L (0.820–0.845) | 0.748 kg/L (0.720–0.775) | Diesel is +11.2% denser |
| 1 Tonne (1,000 kg) Volume | 1,202 Litres | 1,337 Litres | Petrol yields 135 L more volume |
| 50-Litre Tank Weight | 41.60 kg | 37.40 kg | Diesel tank is 4.2 kg heavier |
| Energy Density per Litre | ~35.8 MJ/L | ~32.2 MJ/L | Diesel has +11.2% more energy/L |
| Expansion Coefficient (β) | 0.00085 /°C | 0.00110 /°C | Petrol expands faster in heat |
1. Why Diesel is 11% Denser than Petrol
Diesel fuel contains heavier, longer paraffinic and aromatic hydrocarbon molecules that pack closer together. This higher molecular density means 1 litre of diesel contains 0.832 kg of combustible hydrocarbons compared to only 0.748 kg in 1 litre of petrol.
2. Energy Content per Litre vs per Kilogram
While petrol has slightly higher energy per kilogram (approx 44.4 MJ/kg vs 43.1 MJ/kg for diesel), diesel's higher density gives it ~12% MORE energy per litre (approx 35.8 MJ/L for diesel vs 32.2 MJ/L for petrol), which directly explains why diesel vehicles achieve greater mileage per litre.
Volume vs Mass Visualizer
Volume Comparison: Why 1 kg Doesn't Always Look the Same
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Molar mass, aqueous concentration curves, specific gravity, and laboratory safety batch calculations.
Frequently Asked Questions
Questions about comparing these materials.