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Diesel fuel is refined from oil

Diesel fuel tanker truck
Diesel Fuel Tanker Truck

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

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

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 for the reduction of 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. All diesel fuel now sold in the United States must have a sulfur content of no more than 15 parts per million.

Last reviewed: October 8, 2015

What is diesel fuel?

Diesel fuel is the common term for the motor vehicle fuel used in the compression ignition engines named for their inventor, German engineer Rudolf Diesel, who patented his original design in 1892.

graphic illustration of a barrel to show the different products that come from a barrel of crude oil: other products 7 gallons, liquified petroleum gases 2 gallons, jet fuel 4 gallons, heavy fuel oil (residual) 1 gallon, other distillates (heating oil) 1 gallon, diesel 11 gallons,  and gasoline 19 gallons.
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Note: A 42 U.S. gallon barrel of crude oil yields about 45 gallons of petroleum products.

Compression ignition means that in a diesel engine, air is compressed inside the cylinder of the engine, and fuel is injected causing an ignition. This ignition occurs because air heats up when it's compressed. Although diesel engines are capable of burning a wide variety of fuels (see the Biodiesel section 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 2014, diesel fuel accounted for about 20% of total U.S. petroleum consumption, and about 22% 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 is that heating oil has historically had higher sulfur content than diesel fuel. This difference has decreased over time as some states in the Northeast are phasing in the ultra-low sulfur content standards for heating oil that are currently in effect for diesel fuel. An average of about 12 to 13 gallons of diesel fuel are produced from each 42-gallon barrel of crude oil in U.S. refineries.

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: January 8, 2016