Mass dampers banned

World champions Renault are one of six teams believed to have been using mass-dampers this year, but the only ones who have perfected the use of the system.

A mass damper is a simple spring that helps to keep the tyres of a Formula One car pressed against the ground – something that is especially effective when bouncing over kerbs.

The problem with the system arose when a number of Renault's rivals suggested to the FIA that the spring constituted a moveable aerodynamic device - which are banned from Formula One.

Following this, the FIA sent a letter to all 11 teams telling them that the dampers were no longer allowed, although this ruling could not be rubber-stamped until today.

All teams removed the system from their cars except for Renault – who left it on their spare car for the German Grand Prix at Hockenheim – saying that the FIA's ruling was wrong.

The FIA then appealed against their own race stewards when they decided to pass mass-dampers as legal for that race.

As it turned out, Renault did not run the dampers in Germany or the Hungary a week later for fear of disqualification from those two races at the hearing.

Their pace however, was seriously affected by the loss of the system, which is thought to be worth two tenths of a second per lap.

Today's verdict also found that the decision of the German race stewards to allow Renault to continue using the system was incorrect.

The FIA said in a statement: "The FIA International Court of Appeal met in Paris on Tuesday, August 22, 2006, to examine the appeal made by the FIA against Decision No. 8 handed down by the Stewards of the Meeting on July 28, 2006, concerning the T car of competitor Mild Seven Renault F1 on the occasion of the Grand Prix of Germany and counting towards the 2006 FIA Formula One World Championship.

"Having heard the explanations of both parties and having examined the various documents and other evidence, the Court quashed decision No. 8 of the Stewards of the Meeting and ruled that use of the device known as a Tuned Mass Damper is an infringement of Article 3.15 of the Formula One Technical Regulations."

Renault team leader Alonso, 25, leads German Michael Schumacher by 10 points in the world championship as the pair prepare for this weekend's Turkish Grand Prix at Istanbul Park.