- Global crude oil prices surged due to intensified Iran war and Strait of Hormuz tensions
- A barrel of crude oil equals 42 US gallons, used as a global industry standard
- US refineries yield about 19-20 gallons petrol, 11-13 gallons diesel per barrel
Global crude oil prices have surged sharply since the Iran war intensified in early 2026. Tensions in the Strait of Hormuz, a chokepoint for roughly 20 per cent of the world's oil and liquefied natural gas exports, have constrained supply flows.
This has pushed benchmarks like Brent and US West Texas Intermediate (WTI) higher. Oil tankers laden with up to 2 million barrels of crude per Very Large Crude Carrier (VLCC) have faced delays, routing challenges and insurance cost spikes, further tightening markets.
In this context, every barrel of oil matters, not just for energy markets but for global economic growth, inflation, and transport costs. A tiny shift in supply or tanker throughput ripples across petrol, diesel, LPG and other refined fuels.
What Is A Barrel Of Crude Oil?
A barrel of oil is not literally a physical wooden barrel but the industry's standard measurement: 42 US gallons (about 159 litres) of crude oil. This unit is used in pricing, production data, refining, shipping and trading globally.
At its core, crude oil is a complex mixture of hydrocarbons -- primarily carbon (82-87 per cent) and hydrogen (12-15 per cent) -- along with trace nitrogen, sulphur and oxygen compounds. Its exact composition varies by source, which in turn affects how much diesel, petrol, LPG and other products can be extracted.
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What Products Come Out of One Barrel
Crude oil isn't sold at the pump -- it must be refined and separated through processes like fractional distillation, cracking and blending.
Refinery Yields (Typical US Data)
- From one 42-gallon barrel of crude oil, US refineries produce on average:
- About 19-20 gallons of motor gasoline (petrol) - the fuel used in cars
- 11-13 gallons of diesel fuel - used in trucks, trains, generators
- 3-4 gallons of jet fuel (kerosene)
- Remaining volume goes into LPG (propane/butane), petrochemical feedstocks, asphalt, still gas, coke and other products
As refined products generally have lower density than crude, the sum of volumes actually slightly exceeds the original 42 gallons -- roughly 45 gallons of finished products due to processing gain.
Proportions in Simple Terms
Though precise yields vary by crude quality and refinery technology:
- Petrol (Gasoline): 40-47%
- Diesel & Distillates: 25-30%
- LPG & Other Light Gases: 5-10%
- Jet Fuel, Heavy Fuel Oil, Asphalt & Others: 15-30%
These percentages shift based on the crude's density (API gravity) and sulfur content. Light sweet crude yields more petrol and diesel, while heavy sour crude yields more heavy products and residues.
LPG (Liquefied Petroleum Gas)
LPG (propane and butane) arises from both crude oil refining and natural gas processing. Though a smaller fraction of a barrel by volume (often 2-6 per cent), LPG is essential for heating, cooking and petrochemical feedstock.
How Much Oil Tankers Carry
Crude oil is moved in huge quantities across oceans by tankers -- massive ships designed to carry liquid bulk. According to maritime classifications:
- VLCC (Very Large Crude Carrier): 2 million barrels
- Suezmax: 800,000-1.2 million barrels
- Aframax: 400,000-800,000 barrels
- Panamax: 350,000-500,000 barrels
- ULCC (Ultra Large Crude Carrier): Up to 3+ million barrels on the largest vessels
So, a single VLCC journey can transport millions of barrels of crude - enough to supply multiple countries for weeks.
Why It Matters
Because petrol, diesel and LPG prices ultimately derive from the crude barrel -- any disruption in crude supply (like the Iran war) has a magnified impact on consumers, refiners and traders worldwide.
Each barrel contains the potential fuel that powers transportation, electricity generation and industrial manufacturing. Even small supply shocks can meaningfully influence pump prices and inflation globally.
