Diesel fuel gas will reach its gel point or pour point if the temperature drops from 6 to 10 degrees Fahrenheit (-14.44 to -12.22 degrees Celsius) below the cloud point. Other sources say that at about 10 to 15 degrees Fahrenheit (-12.22 to -9.44 degrees Celsius) the fuel will completely gel, clogging your tank, lines and fuel filters.
Diesel becomes gel because it is comprised of straight and branched chain hydrocarbons (also called paraffin waxes). The amount of paraffin wax diesel contains depends on the type of crude oil used to create the diesel fuel and the process used to manufacture it.
At the North American International Auto Show in Detroit this week, it's not all hybrids and battery-powered cars. Some car companies are making significant investments in a fuel that's not new at all — diesel. Find out more at NPR.