What type of fuel is most commonly stored in underground tanks?

Diesel fuel is the most commonly stored fuel in underground tanks primarily due to its widespread use in transportation, agriculture, and industry. Diesel engines are prevalent in heavy-duty vehicles, such as trucks and buses, as well as in stationary equipment, making diesel an essential fuel type that requires substantial storage solutions.

Underground tanks provide the necessary protection and stability for diesel fuel, keeping it secure from environmental exposure and reducing the risk of evaporation, which can be a concern for other lighter fuels, like petrol. Additionally, diesel has a higher energy density compared to petrol, supporting its long-term storage practicality.

While petrol is also stored in underground tanks, its volatility and tendency to evaporate make it less ideal for prolonged storage in certain environments. Jet fuel, while critical for aviation, is not as commonly stored in underground tanks as diesel and petrol. Ethanol, though increasingly used, is typically blended with petrol and stored accordingly, rather than being stored independently and in large quantities in underground facilities. Thus, diesel's combination of demand and suitable storage characteristics affirms its status as the most common fuel in underground tanks.