What is Clean Diesel?

In today’s world of high pressure common rail injection systems, government emissions standards, fuel economy standards and engine manufacturer warranties the definition of “clean diesel” has become more important than ever to fleet operators.

The International Organization for Standardization’s ISO 4406 contamination codes are most commonly used to express fluid cleanliness. For diesel fuel, the ISO 4406 measures 4, 6 and 14micron size particulate per 100 milliliters of diesel to determine the cleanliness rating. Code numbers range from 1-24 with 1 being the cleanest to 24 being dirty.

The target rating code for today’s ultra-low sulfur diesel (ULSD) fuel is 14 (8,000-16,000 – 4micron particles per 100 milliliters of diesel), 13 (4,000-8,000 – 6micron particles per 100 milliliters of diesel) and 11 (1,000-2,000 14micron particles per 100 milliliters of diesel).

In comparison a typical 7,500 gallon transport load of diesel, has an ISO 4406 rating of 22 (2,000,000-4,000,000 -4micron particles per 100 milliliters of diesel) 21 (1,000,000-2,000,000 -6micron particles per 100 milliliters of diesel) 18 (130,000-250,000 14micron particles per 100 milliliters of diesel)

Fuel analysis done by a qualified lab is the only way to measure fuel cleanliness and identify what the ISO 4406 rating is for diesel fuel coming out of your tank and going into your equipment. Engine manufacturers are using the ISO 4406 rating to determine if fuel system related failures are covered by the warranty. In other words if your fuel is dirty the OEM may not be obligated to honor a warranty naming “dirty fuel” as the culprit.

Next time we will talk about Clean Diesel Fuel management – the actions you can take to get and keep your fuel clean and help your fleet improve fuel economy, protect sophisticated fuel system components, increase unit reliability and meet emission standards.

John Cummins, Vice President of Technology, Hydrotex

Mike McLaughlin, Division Partner-West Texas, Hydrotex

This blog originally appeared on Fleetpros.org

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