Diesel fuel quality varies by location depending on the nature of the crude oil and refining practices used to make it. AMSOIL diesel fuel additives are designed to address variations in diesel fuel quality.
Diesel Fuel Defined
Diesel fuel is any liquid fuel used in a diesel engine. The most common type is a specific fraction distillate of petroleum fuel oil often called petro diesel to distinguish it from non-petroleum alternatives, including biodiesel, biomass-to-liquid (BTL) or gas-to-liquid (GTL) diesel.
Diesel fuel is heavier and oilier than other types of fuel. It has a complex chemical structure with many different compounds. Compared to gasoline, diesel evaporates more slowly and features higher energy density (approximately 147,000 BTUs/gal. vs. approximately 125,000 BTUs/gal. for gasoline). Increased fuel efficiency is one benefit many diesels owners cite when opting for a diesel vehicle.
Ultra-Low-Sulfur Diesel Fuel (ULSD)
Hydro-treating, a refining process that removes sulfur, produces ULSD, which became widely available in the U.S. in 2006.
ULSD is diesel fuel with no more than 15 ppm sulfur. Environmental Protection Agency (EPA) requirements dictated that ULSD comprise 80% of the highway diesel fuel in the U.S. The percentage increased to 100% in 2010.
These fuel requirements, coupled with advanced emission-control technologies, decrease emissions from newer engines by more than 90% and help decrease emissions from older diesel engines, too.
Increased Pump And Injector Wear
To guard against catastrophic wear, diesel fuel must have a minimum level of lubricity. Diesel lubricity is largely provided by trace levels of naturally occurring polar compounds that form a protective layer on metal surfaces.
The hydrotreating process used to reduce sulfur can alter polar compounds and reduce lubricity, increasing wear to the fuel pump and injectors and possibly leading to engine failure.
As such, the lubrication properties of fuel have become a key parameter of diesel fuel specifications, particularly in ULSD.
What Is Biodiesel?
Biodiesel is a biodegradable, renewable source of energy that continues to command interest. Biodiesel fuels are made from agricultural or animal products, such as corn, coconut, chicken or fish.
Agricultural oils have high concentrations of fatty acid methyl esters, which provide better performance than animal-based oils. Due to the ester content of the fuel, using low levels of biodiesel can increase the life of fuel injection equipment that relies on the fuel for lubrication.
Biodiesel is commonly blended with diesel for the retail marketplace. Biodiesel can be used in pure form (100% biodiesel is referred to as B100) or may be blended with diesel at any concentration to be used in most diesel engines. Common blends include B2, B5 and B20. Tests have shown that the addition of a small amount of biodiesel can significantly increase the lubricity of fuel. However, biodiesel can negatively affect gaskets, seals and hoses due to the different solvent properties of the fuel.