The United States used more than 20 million barrels of crude oil per day in 2007, reports Nation Master. Second place in consumption is China with approximately 7.5 million barrels per day. In the United States, the oil that is used for transportation is delivered by oil tanker trucks. (See reference 2.)

Single-tank trucks

Single-tank trucks that have two axles have a carrying capacity of 3,000 gallons of fuel. Fuel trucks with three axles have a maximum capacity of 5,000 gallons of diesel fuel. (See reference 1.)


Trucks with a semi-trailer configuration have one fuel storage tank. The tank is about 40 feet wide and can carry 9,000 gallons of gasoline. (See reference 1.)


Tanks are typically made of aluminum. They are created to be lightweight to carry more fuel. Other tank trailers are made out of carbon steel or stainless steel, especially if they are smaller tanker trucks, if the weight limits are not as much of an issue, and a stronger hold is necessary (See reference 1.)


Fuel tanks are typically made with two to four compartments, or baffles. Bulkheads separate the different compartments in the tanker truck hold. For tanks that carry different flammable material, like petroleum gas, natural gas or propane, double bulkheads are a requirement. This is also true of large tanker trailers that fill up with hazardous materials or industrial chemicals (See reference 1.)


Fuel is unloaded from tankers from the bottom. Gravity allows the fuel to flow through valves inside the tanker into pipes that have been embedded in the ground at your local gas station. The pumping system for liquid cargo is run by air, mechanically or both. (See reference 1.)