A look at types of crude oil, distinguished by properties like heaviness and sweetness

An overview of crude oil, including its constituent hydrocarbons and refinement outputs

The mixture is primarily composed of molecules of carbon and hydrogen atoms bonded into a variety of shapes and lengths, giving each different chemical properties, such as boiling points. Refining can remove elemental impurities—such as sulfur—after hydrocarbons are separated, ensuring the resulting products can be used effectively in other machines, such as car engines.

Crude oil is the type of oil used to create fuel like gasoline, heating oil, and more

Technically speaking, crude oil is unrefined petroleum. This article dives into the different ways it’s categorized (by density, sulfur content, and origin), and how the combinations of these types of oil are used.

How crude oil is split across oil markets based on geographic origin

Brent, West Texas Intermediate, and Dubai are the three crude oil classes and differ in terms of typical refinery uses, density, sulfur content, and suitability for financial benchmarking. Brent, which originates in the North Sea, is traders' go-to benchmark, in part, because it is easily shipped and politically stable, and used to price most of the crude sold internationally.

View the 45 gallons of refined products created from each 42-gallon barrel of crude oil

More than 85% is refined into fuels, such as gasoline and diesel, while about 10% is converted into raw materials for plastics, synthetic rubbers, and other essential products, such as lubricants. Because the majority of these products are less dense than the starting crude oil and additional inputs are introduced during the refining process, there is a processing gain of three gallons.

An animated visualization of the distillation of crude oil into petroleum products

When crude oil is boiled, its constituent hydrocarbons turn into steam and rise through a distillation tower, where temperature decreases with height. Because different chemical vapors cool back into liquids at distinct temperatures, hydrocarbons naturally sort themselves by boiling point and can then be processed separately into distinct outputs.

The US shipped nearly 4 billion barrels of oil abroad in 2024

More than half of the US’s oil is exported as the country produces mainly light, sweet crude but has many refineries that handle heavy, sour types.

The story of the first commercial US oil well and why crude oil is measured in barrels

The 1859 oil discovery in Titusville, Pennsylvania, sparked a boom in oil exploration and production to meet the demand for kerosene lamp fuel. Because the 42-gallon barrel was a readily available container already in use for shipping fish, butter, wine, and other goods, it was adopted by the Petroleum Producers Association in 1872 and by both the US Geological Survey and the US Bureau of Mines in 1882.

See how sugar stacks up against the sweetness of sugar alternatives

This US Food and Drug Administration graphic compares different approved sugar alternatives to give the public a sense of just how intensely sweet these sweeteners are compared to table sugar. Aspartame (NutraSweet and Equal), for example, is 200 times sweeter, Sucralose (Splenda) is 600 times sweeter, and Saccharin (Sweet'N Low) is between 200 and 700 times sweeter.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

The vast majority of Champagne is labeled 'dry' or even 'extra dry'

Sweetness levels are determined by the amount of sugar added to the wine at the end of the process—anything up to 6 grams per liter is extra dry, and up to 12 grams per liter is still considered dry.

Understanding the causes and environmental impacts of crude oil spills and leaks

Although some oil regularly leaks from the bottom of the oceans through the gradual erosion of sedimentary rock, major spills result from accidental ruptures of pipelines or damage to transportation vessels or rigs. Oil can break down the water-repelling ability of feathers, remove the insulation of fur, and poison food chains if ingested.

A case study of how engineers and geologists at Tullow Oil look for oil reserves

An analysis of surface rocks using aerial and satellite imagery can help narrow the search for crude oil by identifying basins where sedimentary layers have compacted—a key process in oil formation. Surveys that look for variations in Earth's gravitational and magnetic fields consistent with specific rock distributions, or that use sound waves reflected off rock layers—not unlike sonar underwater—can also help map subsurface geology.

Rising fracking rates have increased prices of some food products

Every fracking well uses approximately 20,000 pounds of guar gum, a thickening and stabilizing agent commonly used in ice cream, salad dressing, and baked goods. The polysaccharide is also a key component in some cosmetics and explosives.

The science (and scams) behind essential oils

Essential oils are a big business, with industry estimates pegging its market size at $10B last year—a number expected to double by 2030. These distilled plant compounds have a long history of both legitimate and exaggerated uses, and many marketed oils are, as the author of this long read claims, just selling wish fulfillment. Revisit some of the history and contemporary use of essential oils with this piece.

Viscosity is a fluid's resistance to flow, which varies with temperature

Liquids become less viscous as temperature increases, while gases become more viscous and therefore flow more slowly. The increased gas collisions at higher temperatures contribute to greater friction between streamlines, increasing viscosity.

What's the difference between an ale and a lager?

The major distinction is that ales are typically fruitier, while lagers are cleaner and crisper. This video breaks down several more of the nuanced differences between the two styles.

Explaining concentrate and how concentrate-derived juice differs from its source

Developed to reduce the volume of goods—thus lowering storage and shipping costs—the concentration process uses pressure and heat to remove water, pulp, and skin from fruits. Concentrates provide significant flavor, sugar, and calories to foods in small quantities, but do not retain most of the fiber, vitamins, and other nutrients from the source fruit.

How texture affects taste

Texture is the brain's interpretation of several sensations, including pressure, as registered by our teeth, tongue, and finger tips, and sound, as recorded by our ears. Texture also speaks to food particle sizes—smaller than 35 microns contributes to the sensation of creamy—and the balance between flavor and mouth time, such as the crunch of a crispy chip or the bounce of a chewy caramel.

The ancient uses of asphalt

Asphalt is derived from bitumen, a naturally occurring byproduct of decomposed organic materials. As one of the thickest forms of petroleum, the substance has been in use by humans and their ancestors for at least 40,000 years for various purposes, including as a sealant, an adhesive, decoration, and more. Learn more about this ancient material here.

The Dow’s price-weighted formula makes stock price matter more than size

Unlike most indices, which weigh companies by market value, the DJIA is price-weighted—meaning higher-priced stocks have more influence on its movements. As a result, a company’s share price matters more than its overall size.

There's a grading room on the eighth floor of the New York Stock Exchange where experts loudly slurp coffee and then spit it out to test its quality

Since many agricultural commodities are traded through futures, testers ensure that the physical product that reaches the market accurately reflects the price. Coffee graders at the NYSE have to pass a four-day-long exam that's only offered every five years and has a less than 10% pass rate.

What is gravity made of?

Our world at very small scales is governed by quantum mechanics, in which forces and energy come in discrete packets. At large scales, our world is governed by gravity, which moves the planets and stars and can create waves in spacetime. To merge...

How to identify baseball pitches

You might be familiar with terms like "fastball," "curve ball," and "change up," but identifying the specific elements of each pitch type—not to mention what constitutes the more specific types like "splitter" and "cutter"—can leave even passionate fans stumped. This helpful guide to the most used pitches in the big leagues allows you to become a pro in just a few minutes.

'Old people' smell is real—it's a chemical buildup when fatty acids on the skin oxidize

The chemical composition of body odor seems to change with age. Later in life, we harbor higher concentrations of a chemical compound called 2-nonenal that forms when omega-7 fatty acids on the skin oxidize, and the skin's natural antioxidant defenses weaken. Commonly called "nonenal", it's the smell widely associated with aging, and it's often described as a grassy or greasy odor.

12% of adults were taking injectable GLP-1 for weight loss according to 2025 survey

Weight loss injectable use rose sharply between 2024 and fall 2025. The percentage of adults who reported taking this class of medicine specifically for weight loss increased to 12.4%, compared with 5.8% in February 2024 when Gallup first measured it.

Check the current Consumer Price Index

The Consumer Price Index is a metric that attempts to capture price changes felt by consumers by averaging a basket of about 80,000 items, each weighted to reflect the impact of changes on households.

The boiling temperature of water decreases with increasing elevation because the molecules need less energy to overcome the lower atmospheric pressure associated with thinner air.

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

Browse a detailed visual analysis of over 200,000 similes—comparisons that often use 'like' or 'as'—from popular fiction to see how frequently writers the same idiomatic expressions.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.

This poison ivy knowledge quiz—accompanied by photos of the plant's varied forms—may help you identify this common rash-inducing growth.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Art theft is the third-largest source of criminal revenues worldwide, thanks in part to the subjective nature of valuing a work of art.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

Telehealth demand for GLP-1s for weight loss is booming as consumers seek easier access.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

The Great Salt Lake's distinct dual coloration results from high-salinity organisms that only live in the northern portion and produce a purple protein.

Prince's sexually explicit 1984 track 'Darling Nikki' attracted the ire of the Parents Music Resource Center, an advocacy group that inspired the Parental Advisory sticker, even though the song ends with a Christian message.

Apeirophobia is an overwhelming fear of living forever, perhaps stemming from the brain's inability to conceptualize an infinite life.

Take a 3D tour of the Hajj, Islam's annual pilgrimage to Mecca, undertaken by over 1.5 million Muslims.

Explore chaos in this simulation of two double pendulums, where small differences in the release angles produce wildly different outcomes.

The 19th-century painters of the Hudson River School were among the first American romantics, with portraits that displayed the natural beauty of the young country.