STANDARD ECU

All cars have a standard electronic control unit (ECU) controlling the engine, gearbox and clutch and designed by McLaren Electronic Systems and Microsoft to a specification set out by the International Automobile Federation (FIA).

The introduction of the unit, which gathers data from more than 100 sensors on each car, has allowed the governing body to ban the use of traction control and other so-called 'driver aids'.

Renault estimate that the loss of such systems, which particularly help drivers in wet and slippery conditions, will cost them up to 0.4 seconds per lap.

Some teams, notably Ferrari and Renault, have suggested the unit could give McLaren an early advantage as makers of the system.

Drivers have raised concerns about the safety of driving without traction control in the wet, while welcoming a move that puts more emphasis on individual skill and could lead to more overtaking.

ENGINE CHANGE

Drivers are allowed one 'free' engine change to their car without the normal 10-place penalty on the starting grid.

This must be a competitor's first change of the season and it must be a result of genuine engine failure rather than for tactical reasons.

Engines still have to last for two successive races. Any unscheduled change, other than the first, will incur a 10-place penalty as before.

HEAD PROTECTION

Drivers have been given increased protection from side impacts at head level by higher cockpit surrounds.

The change followed last year's Australian Grand Prix when David Coulthard's Red Bull passed over the Williams driven by Alexander Wurz, narrowly missing the Austrian's head.

BIO-FUEL

A minimum of 5.75 percent of the fuel must be derived from biological sources.

SPARE CARS

Each team is allowed no more than two cars available for use at any one time at a grand prix. The rule effectively means there will no longer be spare cars in the garages.

GEARBOX

Gearboxes must now last for four successive races (Saturday/Sunday). Any unscheduled replacement will incur a five-place penalty on the starting grid at that event.

Like engines, gearboxes can be changed for the subsequent race if a driver fails to finish for reasons beyond his or the team's control.

QUALIFYING

Refuelling is not allowed between the end of qualifying and the start of the grand prix. Teams are likely to run shorter first stints in the race.