The Basics

There are important changes to the Formula 1 rules and regulations in 2009. These are the most significant changes in recent years.

Slick tyres, which have been outlawed since 1998, are back. This will provide the cars with more grip to make up for losses in aerodynamic grip which has been reduced significantly with new rules. Bridgestone will continue to be the sole supplier of F1 tyres, and drivers will still have to use both compounds available in the course of a race.

The aerodynamics are very different with the cars much tidier following a ban on aerodynamic appendages. Front wings will be lower and wider, while rear wings will be much higher and narrower. This was designed to improve overtaking after a lengthy study by the Overtaking Working Group. The diffuser at the rear of the car has been moved back and upwards in order to reduce the ability of the car to create ground-effect. For the first time in the modern era drivers will be able to adjust the flaps on the front wing by up to six degrees, although this will be limited to only two adjustments per lap.

This year also sees the introduction of kinetic energy recovery systems. These are regenerative braking systems which are designed to recover some of the vehicle's kinetic energy, which is normally dissipated as heat. The recovered energy can be stored electrically, in a battery or supercapacitor, or mechanically, in a flywheel. The power stored in the car can then be used as "boost". This is limited to a maximum of 82 horsepower for six seconds per lap. KERS is not compulsory and many teams are not going to use the systems at the start of the 2009 season as they are not yet sufficiently developed.

There is a complete ban on in-season testing.

Cars are restricted to eight engines per season and the maximum rev limit has been reduced to 18,000rpm. This means that the average life of an engine increases from around 1200km to 2500km.

Teams have been allowed to carry out some work on the engines to address reliability issues, with the specification frozen at the end of March. The only elements that can be changed are the inlet trumpets, the position of the injectors and the configuration of the exhaust system. If a reliability issue occurs during the coming season, an engine manufacturer can ask the FIA for permission to take action to resolve it, as long as this is approved by all the other teams.

The Safety Car rule has been changed to allow cars to enter the pits without them having to be opened.