The Australian Grand Prix next weekend will see the introduction of sweeping rule changes designed to bring competition and excitement back into Formula One, even if some of the teams would rather have been left with the status quo.

Among those changes causing a little unrest in the paddock are the restrictions being placed on the use of the spare car. Whereas teams used to be able to take as many cars as they wished to races - usually three but, in the case of Ferrari, sometimes four - and have them all scrutineered for use as and when permitted by the 'old' rules, things will be different in 2003.

Only two cars per team will undergo initial scrutineering prior to opening practice on Friday, and no further cars will be scrutineered unless, in the opinion of the FIA technical delegate, one of the original pair is deemed beyond repair after being damaged in an accident on the track. Any mechanical failure on one of the two cars scrutineered which occurs prior to the end of the second qualifying session will not be considered grounds for use of a spare car.

If a car is damaged beyond repair and a spare car is required between free and qualifying practice, this spare car will become the relevant driver's race car. If the original car is subsequently repaired, it will become the spare and be re-scrutineered if needed.

The FIA technical delegate will normally carry out the bulk of the scrutineering checks on any spare car present before the race itself. If any cars are needed before the start of the race, final checks will be carried out and scrutineering stickers issued accordingly.

In order to ensure that no team needing to use a spare car is disadvantaged as a result of any unforeseen delay in scrutineering, the stickers will not become valid, and no spare car may enter the pit lane, until the pit exit is closed for the race. If a driver uses a spare car under these circumstances, no restrictions on fuel load will be applied and, if the FIA technical delegate feels it is not feasible to fit the tyres used for qualifying, tyres may be changed.

If a race car is damaged in an accident which necessitated a race stoppage within the first two laps, a spare car may only be used if the FIA technical delegate is satisfied that the original car cannot be repaired in time for the re-start. In order that he may establish whether or not a car is damaged beyond immediate repair, the scrutineering stickers already issued will be deemed invalid from the time the race was stopped until the time at which the pit exit closes for the re-start.

In accordance with article 156 of the sporting regulations, any driver forced to start from the pit-lane after the first start will be able to start from his original grid position at the re-start in either car.

As cars are not specifically assigned to drivers, they may use either of the two cars their team has presented for initial scrutineering. However, if a driver changes car at any time after the second qualifying practice session, he must start the race with the same amount of fuel that remained in his original car following the timed session. This will be established by weighing the car and comparing it with that taken during the second qualifying session, no variation greater than 3kg will be permitted.

Furthermore, if there is any reason to suspect that a change of car was carried out systematically, or for reasons other than mechanical failure of the original car, the team concerned will be reported to the stewards of the meeting under article 149 of the sporting regulations.