These companies – Booster Fuels, WeFuel, Filld, Yoshi, and Purple among them – offer apps that allow users to order a gas-tank refill. Small tanker trucks are dispatched at varying intervals to fill up the car. It's a subject that led to some good-natured debate around the office, and clearly these services aren't for everyone. But if you ask the fire departments in the major cities where the services are hoping to operate, and regardless of whether the cities are in favor of the service or not, the laws on the books generally make them illegal.
Most cities have laws and codes that regulate fuel delivery and servicing, in addition to state- and federal-level requirements. As the services are currently structured, it'd be illegal in San Francisco. And Los Angeles' fire code currently doesn't allow it, although Bloomberg reports that the city is looking for a way to amend the fire code to let the services operate. Whether the restrictions eventually imposed prove to be a hardship for these startups remains to be seen.