The oil barrel equals 158.987 litres or 42 US gallons. It is the global pricing unit for crude oil and petroleum products. The US dry barrel (115.6 L) and UK beer barrel (163.7 L) are different units that share the same name.
Real-world: Brent crude and WTI oil are priced in US dollars per barrel. Global oil demand is about 100 million barrels per day.
Read full barrel reference โThe UK imperial gallon equals 4.54609 litres exactly. Defined in 1824 as the volume of 10 pounds of water at 62 ยฐF. Still used for fuel economy reporting in the UK and some older industrial contexts. The UK imperial gallon is about 20% larger than the US gallon.
Real-world: UK petrol sold by litre since 1995, but economy is quoted in UK mpg: a diesel car at 60 mpg (UK) uses 4.7 L/100 km.
Read full uk gallon reference โ