‘Think of the CN for diesel as one would for the octane rating of gasoline—only opposite in meaning. That’s because the higher the octane rating of gasoline, the slower it ignites, which stops detonation, or pinging. A high CN means the fuel ignites faster, producing a longer, cleaner fuel burn than diesel with a lower CN.
A cleaner diesel fuel burn means lower emissions. That’s why the U.S. Environmental Protection Agency, the government’s air-quality police, set a minimum CN of 40 across the country, with the final CN left up to individual states’ EPA regulations. For example, the California Air Resources Board (CARB) currently mandates a minimum 53 CN, while Texas (TxLED) set its highway diesel CN lower, at a minimum of 48.’
“Cetane Number.” It’s a rating in the diesel world that perks up our ears. We know it’s an important variable in the fuel that powers our rigs. But for most of
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