New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Ethanol fuel

The use of ethanol as a fuel for internal combustion engines, either alone or in combination with other fuels, has been given much attention mostly because of its possible environmental and long-term economical advantages over fossil fuel. Ethanol fuel is an alternative to gasoline. It can be combined with gasoline in any concentration up to pure ethanol (E100). Anhydrous ethanol, that is, ethanol without water, can be blended with gasoline in varying quantities to reduce the consumption of petroleum fuels, as well as to reduce air pollution. In the US, tolerance of ethanol depends on the individual vehicle.

In Brazil, ethanol-powered and flexible-fuel vehicles are capable of running on hydrated ethanol, an azeotrope of ethanol and water. In addition, flexible-fuel vehicles can run on any mixture of hydrated ethanol and gasoline, as long as there is at least 20% ethanol. A few flexible-fuel systems, like the Hi-Flex, used by Renault and Fiat, can also run with pure gasoline.

Ethanol is increasingly used as an oxygenate additive for standard gasoline, as a replacement for methyl t-butyl ether (MTBE), the latter chemical being responsible for considerable groundwater and soil contamination. Ethanol can also be used to power fuel cells and to produce biodiesel.

Related Stories
 


Earth & Climate News

May 9, 2026

Beneath the beauty of coral reefs lies a hidden universe of microbes unlike anything scientists expected. Each coral species supports its own specialized microbial partners, many of which have never ...
Cumberland, B.C. is reimagining its coal mining past as a clean energy opportunity. Water trapped in abandoned mine tunnels could be used in a geothermal system to heat and cool buildings efficiently and with minimal emissions. The project could ...
Southern Alaska’s winter finale delivered a spectacular atmospheric display, captured by a NASA satellite. Cold Arctic air flowing over warmer ocean waters created long bands of clouds, swirling vortex patterns, and even a compact polar storm with ...
Greenland’s ice sheet is now melting in ways never seen before, with extreme events becoming more frequent, widespread, and intense. Since 1990, meltwater production has skyrocketed, and most record-breaking events have occurred in recent years. ...
Scientists are using sunlight to turn plastic waste into clean fuels like hydrogen, offering a breakthrough solution to both pollution and energy challenges. While still in development, the approach could transform trash into a valuable resource for ...
Long before humans spread across the globe, a deadly disease may have quietly shaped where our ancestors lived—and even how we evolved. New research reveals that malaria didn’t just threaten early human survival; it actively pushed populations ...
Crabs’ famous sideways walk may trace back to a single evolutionary moment 200 million years ago. Researchers found that most modern crabs inherited this trait from one ancestor—and never looked back. The movement likely gave them an edge, ...
Two of the most dangerous fault systems on the U.S. West Coast may be more connected than scientists once thought. New research suggests the Cascadia subduction zone and the San Andreas fault can “sync up,” triggering earthquakes within minutes ...
Scientists have uncovered a tiny wall-dwelling spider named Pikelinia floydmuraria, inspired by Pink Floyd. Despite its size, it’s a fierce predator that hunts ants much larger than itself and helps reduce common urban pests like mosquitoes and ...
Australia’s famous Twelve Apostles didn’t just erode into existence—they were slowly pushed up from the ocean floor by powerful tectonic forces over millions of years, new research reveals. Scientists discovered that these towering limestone ...
Deep beneath the Southern Ocean, a quiet but alarming shift is underway: warm water is creeping closer to Antarctica, and scientists are now seeing it clearly for the first time. By combining decades of ship data with robotic float measurements and ...
For the first time, scientists have watched a subduction zone literally fall apart beneath the ocean floor. Using advanced seismic imaging, they found the Juan de Fuca plate splitting into fragments as it sinks beneath North America. Rather than ...

Latest Headlines

updated 12:56 pm ET