Liberal Forum

Blackvegetable » Yesterday, 7:22 am » wrote: ↑

Yesterday, 7:22 am

What are you? 

A **** idiot?  

Yes, California has unique and stricter standards for diesel fuel compared to the rest of the United States, commonly referred to as CARB diesel.

[1]  Regulated by the California Air Resources Board (CARB), these rules set strict limits on fuel properties to reduce air pollution. [2, 3, 4]  

Key Differences in CARB Diesel Standards

Aromatic Hydrocarbons: California limits aromatic hydrocarbons to a maximum of 10% by volume (or an equivalent alternative formulation), which significantly reduces nitrogen oxide ($NO_x$) and particulate emissions. Federal standards do not cap aromatics this tightly.

Sulfur Content: While federal standards now match California's ultra-low sulfur limit of 15 parts per million (ppm) for highway diesel, California pioneered low-sulfur requirements decades earlier and maintains strict enforcement.

Lubricity Standards: California enforces a specific lubricity requirement (a maximum HFRR wear scar diameter of 520 µm) to ensure that removing sulfur and aromatics does not cause excessive wear on fuel injection equipment.

Renewable Diesel Mandates: California requires specific fleets (such as public and certain off-road or transit fleets) to use high-purity renewable diesel formulations like R99 or R100 under its Alternative Diesel Fuel regulations. [1, 6]