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Diesel fuel is refined from oil

Diesel fuel tanker truck
Diesel Fuel Tanker Truck

Source: Stock photography (copyrighted)

Diesel fuel is used in the diesel engines found in most freight trucks, trains, buses, boats, and farm and construction vehicles, and in some cars and small trucks. Diesel fuel is also used in diesel engine generators to generate electricity, such as in remote villages in Alaska, among other locations around the word. Many industrial facilities, large buildings, institutional facilities, hospitals, and electric utilities have diesel generators for backup and emergency power supply.

Diesel fuel is a type of distillate fuel. On average, about 12 gallons to 13 gallons of distillate are produced from each 42-gallon barrel of crude oil in U.S. refineries, with the majority sold as diesel fuel.

Before 2015, diesel fuel sold in the United States contained high quantities of sulfur. Sulfur in diesel fuel produces air pollution emissions that are harmful to human health. In 2006, the U.S. Environmental Protection Agency issued requirements to reduce the sulfur content of diesel fuel. The requirements phased in over time, beginning with diesel fuel sold for vehicles used on roadways and eventually covering all diesel fuel. Most of the diesel fuel now sold in the United States for use in vehicles is ultra-low sulfur distillate/diesel, which has a sulfur content of 15 parts per million or less.

Last updated: September 28, 2018

What is diesel fuel?

Diesel fuel is the common term for the distillate fuel oil sold for use in motor vehicles that use the compression ignition engine named for its inventor, German engineer Rudolf Diesel. He patented his original design in 1892.

Compression ignition means that in a diesel engine, air is compressed inside the cylinders of the engine, which causes the air in the cylinders to heat up. When fuel is injected into the cylinders of hot, compressed air, the fuel ignites. Although diesel engines are capable of burning a wide variety of fuels (see the section on biodiesel below), most of the diesel fuel consumed is refined from crude oil.

Nearly all semi-trailer trucks, delivery vehicles, buses, trains, ships, boats, and barges have diesel engines. Farm vehicles, construction vehicles, and military vehicles and equipment also have diesel engines. Some diesel fuel is also used for electricity generation. In 2017, distillate fuel oil accounted for about 21% of total petroleum consumption by the transportation sector.

Most diesel fuel is made from crude oil

Diesel fuel is refined from crude oil at petroleum refineries. Diesel fuel and heating oil are distillate fuels. The main difference between the two fuels has been the sulfur content, with heating oil having a higher sulfur content. This difference has decreased over time as some states in the Northeast are phasing in ultra-low sulfur content standards for heating oil that are already in effect for diesel fuel. An average of about 11 gallons to 12 gallons of diesel fuel are produced from each 42-gallon (U.S.) barrel of crude oil that U.S. refineries process.

Diesel fuel may contain biodiesel

One of the fuels that Rudolf Diesel originally considered for his engine was vegetable seed oil, an idea that eventually contributed to biodiesel production. Blends of up to 20% biodiesel with 80% petroleum diesel (B20) can generally be used in unmodified diesel engines.

Last updated: August 8, 2018