What the sporting regulations say:
- Cars may use no more than 105kg of fuel in each race (with the power unit regulations stipulating that fuel flow must not exceed 100kg/hour). Drivers exceeding the fuel limit during a race will be immediately excluded from the race results.
- Teams are not permitted to add or remove fuel from a car during a race. In other occasions during the weekend they may refuel cars but only in their respective garages, and only at a rate of 0.8 litres per second.
What the technical regulations say:
- Formula 1 cars run on petrol, the specification of which is not significantly removed from that used in regular road cars.
- All fuels must comply with strict requirements, and prior to each event the teams must submit two separate five-litre samples to the FIA for analysis and approval. Fuel samples will also be taken during an event to ensure the fuel being used is legal.
- Fuel tanks are also strictly governed - they must comprise a single rubber bladder, which must be made of materials approved by the FIA and must be manufactured by certain approved companies.
- The tank must be situated directly behind the driver and directly ahead of the engine. All fuel lines must be self-sealing in the event of an accident and no lines must pass through the cockpit.
- The fuel tank must be encased within a crushable structure that forms part of the car's safety cell. This structure must be able to withstand very high impact loads as specified in the regulations.