FIA appointed scrutineers have the power to check all cars at any point during an Event to ensure their legality and safety – a car cannot take part in the Event until it has passed scrutineering.
Initial scrutineering takes place in teams’ garages between 10:00 and 16:00 (local time) on Thursday before the race (Wednesday at Monaco) and cars must be examined again if significant changes are made or they were involved in an accident.
Cars are weighed during the Grand Prix weekend to ensure they comply with minimum weight requirements (722 kg + tyres).
Any car taking part in FP1, FP2 and FP3 may be randomly selected and weighed at the end of each of sessions.
Any car taking part in Q1 and Q2 parts of qualifying can be randomly selected and weighed while all cars taking part in Q3 must be weighed after the session.
All classified drivers are weighed again after the race. If a driver wishes to leave his car before it’s weighed, he must ask the technical delegate do weigh him.
Any competitor failing to meet the minimum weight requirements may lose their qualifying times or be excluded from the race results unless this happened due to the accidental loss of any part of the car, which has to be proved to technical delegates.
Cars are weighed with dry-weather tyres fitted – if a car does not already have them fitted, it will be weighed on a set of dry-weather tyred selected by the FIA technical delegate.
FIA F1 2017. sporting regulations can be downloaded here.