The industry standard for tanker trucks hauling crude oil is 210 barrels, or just over 8,800 gallons. However, tanker trucks with other capacities, such as 50, 100 or 300 barrels, are also relatively common. The majority of trucks have capacities ranging from 5,500 to 11,600 gallons.
Larger tanker trucks are generally used for transporting liquids over long distances. For example, they may carry oil from a pipeline or well to a processing plant. Smaller tanker trucks, those with a capacity of less than 5,000 gallons, are typically used within a local community. For example, trucks with a capacity of around 3,000 gallons are often used for septic tank cleaning and transport.