The Challenges of High Pressure Common-Rail Systems

Today’s diesel engines use high pressure common-rail (HPCR) direct injection technology to provide greater efficiencies compared to conventional diesel engines. These engines operate under higher temperatures and pressures that can cause standard #2 diesel to break down into carbon deposits, which lead to reduced performance and even engine damage. These deposits can occur in two places:

Nozzle Coking Deposits

Nozzle coking, or deposits in the injector tips, has been an issue for years. Injector nozzles spray microscopic fuel droplets and become clogged by the smallest deposits. Even a stain or varnish clog can lead to decreased power and fuel efficiency.

Internal Diesel Injector Deposits (IDID)

In recent years, IDID have become an issue in the new HPCR systems. Unlike nozzle coking deposits, IDID form deep inside the high-precision injectors. Because these components have tight tolerances, as low as 1-3 microns (human hair is 70-100 microns thick), even the most minimal deposits can significantly reduce power and fuel economy and, in some cases, result in injector failure. 

Fuel Filter Plugging

In addition to deposits forming in the fuel injection system, another known issue with HPCR systems is premature fuel filter plugging. Fuel filters capture unwanted contaminants from the fuel that can cause serious damage if left unchecked. As the flow of the fuel through the fuel filter becomes restricted or plugged, a loss of power will result. 

Meeting the Demands of High-Tech Engines

Nearly all U.S. original equipment manufacturers (OEMs) have experienced issues with injector deposits in testing or field trials. It’s important that diesel owners use premium diesel fuels that contain injection stabilizers to guard against IDID, especially in newer vehicles.

Laboratory and field tests confirm the upgraded injection stabilizer in Cenex premium diesel fuels successfully removes and prevents IDID, including carbonaceous, soap/metal carboxylates and lacquer type deposits, as well as a dramatic reduction in fuel filter plugging while maximizing power in today’s high tech engines.


Cenex Premium Diesel Fuels come with a more complete additive package for a more complete burn that:

Cenex Roadmaster XL® and Cenex Ruby Fieldmaster® both contain the following additives, which help maximize fuel performance, reduce downtime, extend injector and injector pump life and provide smoother, quicker starts.

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