Diesel Fuel Additives

Additives Correct & Enhance Fuel 

Additives are used to modify the properties of diesel. These include detergents, corrosion inhibitors, lubricity, cetane and cold flow improvers. Additives are blended into the diesel at virtually every stage of the distribution process, from refinery to vehicle. Proper dosing and blending are critical so that additives function as intended and do not cause unintended negative consequences. Additives have many benefits, but must be proven fit for purpose in the specific application. With the exception of chemicals that pose a health hazard (such as lead) additives are generally not regulated. 

Before shipping a product, refineries must ensure that it meets specific property requirements and is suitable for the intended use. To accomplish this, they carefully calculate and control their crude oil selections, refining and blending processes, and additive packages. In some cases, a particular fuel property can be achieved in more than one way. Some refineries produce high quality fuel with these properties through refining processes alone. Others choose to supplement with chemical additives to ensure the same specification is met. 

Additives frequently blended in at the refinery include: 
      • ​Cetane improvers 
      • Pour point reducers (cloud point is usually addressed through process changes) 
      • Cold filter plugging point improvers (Europe) 
      • Anti-foaming agents (Europe & Asia) 
      • Fuel stability improvers 
      • Lubricity improvers (used worldwide with ULSD) 

Reputable fuel distributors test fuel upon delivery and additize as necessary to ensure that it meets industry specifications and local needs (such as cold weather operability). They should have the equipment and expertise needed to dose and blend properly. 

Sometimes the fuel is further enhanced in order to sell it as higher quality. It often includes the 
following additives:
      • Corrosion inhibitors (added by refineries/pipeline operators)  
      • Detergents/dispersants 
      • Stabilizers 
      • Cetane improvers 
      • Cold weather operability enhancers 
      • Biocides 

These are additives put in by the end user. A wide variety of aftermarket additives are sold, some with very legitimate purposes and some with improbable claims as "miracle cures" for a whole range of real or fictitious problems. Users should be very careful when deciding to use or not use a particular additive; most desirable diesel characteristics (cetane numbers, lubricity...) have already been ensured by the refinery or distributor. 

Generally speaking, aftermarket additives should be avoided unless a reputable manufacturer has previously tested your fuel chemistry and tank conditions before making a recommendation. Fuel from a reliable source will already contain additives, it is imperative that overtreatment doesn’t occur. Often, if there is an abundance of additives, they can react to form an insoluble contaminant that will plug high efficiency fuel filters. Additive manufacturers and refineries test extensively to ensure that recommended additive packages and fuel elements do not have undesirable reactions between themselves. The end user has no specialized equipment and cannot possibly know all the various components of the diesel in his tank, so he faces a greater risk of adverse chemical reactions between substances.
If, after appropriate research, the end user decides to use a certain additive, it is essential that manufacturer instructions be followed carefully. Respect recommended dosages and blending practices. For example, there is frequently a minimum recommended temperature under which the additive may not completely dissolve into the fuel. Potentially, this can cause filter plugging and other issues that make problems worse instead of fixing them. A word of caution, engine manufacturers may state that certain additives may not be used in their equipment. The user will be held responsible for any alteration of fuel that makes it unfit for use.