What is Diesel Fuel?

Diesel fuel is a very complex mixture of thousands of individual compounds with carbon numbers between 9 and 23 (number of carbon atoms per hydrocarbon* molecule) Most of these compounds are members of the paraffinic, naphthenic or aromatic class of hydrocarbons (HC). These three classes have different chemical and physical properties.
The different relative proportions of the three classes is one of the factors that make one diesel fuel different from another. It influences fuel properties and affects its performance.

Up until about 15-20 years ago, refineries used only about 50% of a barrel of crude oil to make distillates such as gasoline, jet fuel and diesel. The remainder of the barrel of crude oil went to "residual oil". Today, as a result of different refining techniques, the refinery uses 90% or more of the same barrel of crude, which has consequences for fuel stability.

Differences In Product Results From Refining Technique Changes

More than 90% of the debris on filter elements and the sludge in our storage tanks is organic material, fuel and oil residue from it's breakdown. In most cases, this debris is acidic and not good for your engine. It causes corrosion in injectors, pumps and storage tanks.

Microscopic Pictures Of Organic Sludge

The solids that form as the result of the inherent instability of the fuel and the natural process of degradation will accumulate in the bottom of your tank. The sludge will form a coating or bio-film on the walls and baffles of the tank, plug your filters and impact combustion efficiency. Eventually it will clog fuel lines and ruin your equipment by wearing at the clearances in injectors and pumps as well as the metal used to build tanks.

*Hydrocarbons are organic compounds composed entirely of carbon and hydrogen divided in four major classes: paraffins, naphthenes, olefins, and aromatics. These classes share common structural features but differ in size, (number of carbon atoms per molecule) and/or geometry. While hydrogen and carbon are the predominant elements in crude oil, small amounts of sulfur, nitrogen and oxygen are also present and referred to as hetero-atoms (other-atoms). Compounds containing hetero-atoms are non-hydrocarbons. Typical non-hydrocarbons found in diesel are dibenzothiophene and carbazole, which play a large role in determining certain fuel properties.

Diesel fuel is a living thing.  It suffers from aging much like any organic compound.  Left sitting diesel fuel will try very hard to revert back to crude.  Rapid use of your fuel does not eliminate this problem, it only prolongs the results.  By taking a proactive approach you can reverse the signs of aging and keep your diesel fuel in optimal quality at all times.  Learn more at Cleanfuelmanagement.com or see additional white papers at