From Consumer Wiki
Gasoline pricing is not regulated by any state or federal agency.
State level has responsibility for measurement standards regulations for advertising, quantity, octane number, price posting, nozzle problems, absence of air, gas pumps or gauge for measuring air pressure. See Weights and Measures (County) for all county offices and phone numbers to report problems or get information.
Department of Food and Agriculture
Division of Measurement Standards
8500 Fruitridge Road
Sacramento, CA 95826
Alternative fuels, the cleaner-burning gasoline program, diesel fuel regulations, plus fuels related enforcement activities.
Air Resources Board
PO Box 2815
1001 I Street
Sacramento, CA 95812
(916) 445-5025 Fax
Gasoline sales with mandatory purchase of additional service (such as a car wash) are prohibited by California Business and Professions Code Section 20735. Complaints are handled by the local county or city District Attorney's Office for the particular county.