Motor Vehicle Fuels Inspections
A primary component of the CARB's Motor Vehicle Fuels Enforcement program is the inspection of California gasoline and diesel fuel at production, transport, and dispensing facilities.
ARB Fuels Inspectors conduct frequent, unannounced inspections of refineries, service stations, distribution and storage, bulk purchaser and consumer facilities throughout the State of California to obtain samples of gasoline and diesel fuel. The samples are then analyzed in the Mobile Fuels Laboratory.
Mobile Fuels Laboratory
The Mobile Fuels Laboratory is a fully-equipped and self-contained vehicle located in the vicinity of the inspection. The Lab contains instrumentation and support equipment necessary for the immediate testing of gasoline and diesel fuel. For more information, visit Mobile Fuels Laboratory.
Fuels Analysis
Tests are conducted on fuels samples for compliance with Phase 3 California Reformulated Gasoline (CaRFG) and diesel fuel regulations.
| Fuel | Properties Analyzed |
|---|---|
| Gasoline (CaRFG) | Reid vapor pressure, T50 and T90 distillation temperatures, total aromatics, olefins, and oxygen, benzene, and sulfur contents. |
| Diesel Fuel | Sulfur, aromatic hydrocarbon content, and polynuclear aromatic hydrocarbon content. |
| Alternative Diesel Fuel Formulations | Sulfur, aromatic hydrocarbon content, polynuclear aromatic hydrocarbon content, nitrogen, cetane number, and additives. |
Specification and Test Methods for California Gasoline, Motor Ethanol, and Diesel Fuel
The following documents offer a brief and informal summary of specifications and test methods:
- Gasoline Specifications and Test Methods
- Motor Ethanol Standards and Test Methods
- Diesel Fuel Specifications and Test Methods
What Happens When a Violation is Discovered?
After violations are documented by inspectors, further investigation is conducted. ARB staff evaluate the data, determine the cause and severity of the violation, and prepare the case. Most cases are resolved through CARB's mutual settlement program or referred for settlement or litigation.
For contact information regarding other ARB Enforcement programs, please visit our Enforcement Contacts web page.