What Is NCWM? NCWM is the National Conference of Weights and Measures. They are a national organization made up of relevant industry groups that sets national standards for products being sold in the United States. Once an agreed upon standard is developed it is recommended by NCWM for adoption by the individual states and municipalities.
Goal of NCWM premium diesel Specification: The goal was to develop a meaningful definition of premium diesel. This was so premium diesel could be:
What is NCWM's definition of premium diesel? Currently there are five properties that NCWM has determined should be included in the definition of premium diesel. All 5 of these properties can be shown to provide an improved benefit to the consumer over D975 spec. They are included below with a brief description.
Energy Content: Diesel Fuels with higher energy content can provide higher power and increased fuel economy to the consumer. The NCWM proposed requirement to meet this criterion is a minimum 138,700 Btu/gallon gross as measured by ASTM Standard Test method D240.
Cetane Number: Higher cetane diesel fuels have been shown to reduce white smoke, reduce noise, reduce engine misfire, provide easier cold starting, and reduce some regulated emissions in many engine types. The NCWM proposed requirement is 47.0, Minimum, Cetane Number as measured by ASTM Standard Test Method D613.
Low Temperature Operability: Under low ambient temperature conditions, wax can precipitate from diesel causing restrictions in fuel flow that can result in engine stall. For a normal winter, providing a fuel capable of operating at lower ambient air temperatures than the ASTM guidelines may provide a benefit to the consumers in winter operation.
The proposed NCWM requirement to meet this criterion is a cold temperature operability measurement equal to the ASTM D975 tenth percentile minimum ambient air temperature charts and maps (see enclosed) by:
Thermal Stability: Diesel Fuel is increasingly used as a coolant for high-pressure fuel injection systems that can thermally stress the fuel. In some cases, this stress can cause the fuel to degrade and form insoluble materials that can restrict fuel flow through filters and injection systems.
The proposed NCWM requirement to meet this criterion is a minimum 80% reflectance measurement using a green filter in the F21-61 stability test (180 minutes, 150 degrees C).
Note: This test method will soon be reviewed for adoption as an ASTM Standard Test Method.
Fuel Injector Cleanliness: The Proposed NCWM Requirement is as follows:
Fuel must meet:
When a detergent additive is used to meet this requirement, the effectiveness must be tested in the test reference fuel (Caterpillar 1-K) in the L-10 test.
If another fuel is used, an L-10 test may need to be run on that specific fuel. Regulators may require the fuel supplier to provide sample and test results once during each calendar year. The regulating authority would determine the time and sampling of testing.
Note: Lubricity is not included in the definition for premium diesel at this time.
Premium Diesel Identification: All products identified on retail dispensers, bills of lading, Invoices, shipping papers, or other documentation as premium, super, supreme, plus, or premier must conform to at least 2 of the 5 recommended requirements listed and described above. Lubricity cannot be used as one of the five requirements.
Labeling Properties of Premium Diesel:
Retail locations must display:
The label must be displayed on the upper 1/2 of the product dispenser front panel in a position clear and conspicuous from the driver's position.
When does this recommendation take effect? January 1, 2000 the regulation becomes officially adopted by NCWM.