What the sporting regulations say:
- A team of specially appointed scrutineers has the power to check cars at any point during a Grand Prix weekend to ensure that they fully comply with technical and safety regulations.
- A car cannot take part in the event until it has passed scrutineering.
- Every car is initially examined in its respective garage on the Thursday of a race meeting (Wednesday at Monaco), with scrutineering commencing 24 hours before the start of first practice and lasting for six hours.
- A car must be re-examined by scrutineers if any significant changes are made to it by the team or if it is involved in an accident.
- In addition to scrutineering, cars are also weighed during the Grand Prix weekend to ensure that they comply with minimum weight requirements (733kg).
- Cars taking part in FP1, FP2 or FP3 may be selected at random to be weighed at the end of each of these sessions.
- Cars taking part in Q1 and Q2 are called in at random to be weighed, while all cars participating in Q3 are weighed after the session.
- Classified finishers are weighed again after the race. If a driver wishes to leave his car before it is weighed he must ask the technical delegate to weigh him in order that this weight may be added to that of the car.
- Any competitor failing to meet the minimum weight may lose their qualifying times or be excluded from the race results unless this is due to the accidental loss of part of the car.
What the technical regulations say:
- Cars must weigh at least 733kg (including the driver and all his safety equipment but not fuel) at all times during an event.
- Cars are always weighed with dry-weather tyres fitted.
- The weight applied on the front and rear wheels must not be less than 333kg and 393kg respectively during qualifying.
- Teams may use ballast to bring cars up to weight but it must be firmly secured to the cars. Ballast may not be removed or added during a race.
- With the exception of compressed gases, no substance may be added to the car during the race. If it becomes necessary to replace any part of the car during the race, the new part must not weigh any more than the original part.