An innovative damper system pioneered by Renault and adopted by several other teams, including Ferrari, has been banned by the FIA, autosport.com can reveal.
With so little to separate the competitiveness of Renault and Ferrari in their battle for the world championship, this week's surprise outlawing of 'mass' dampers could have an impact in the outcome of the title fight.
Mass dampers are simple mechanical devices that comprise of a weight, believed to be around 9kg, mounted in a spring. They improve a car's performance by dampening out tyre bouncing frequencies throughout corners and therefore keeping grip levels more consistent.
Renault were believed to be the first to use the device, although they have never officially confirmed that they were running with it. Red Bull Racing, Williams, Ferrari and most recently McLaren have subsequently developed their own systems.
Autosport's technical consultant Gary Anderson told Autosport earlier this year: "You see a car bouncing, such as when it hits a kerb. This will be around 8-9Hz (hertz, unit of frequency equal to one cycle per second) on the tyres.
"This device will get an equal frequency going in the opposite direction. It's a bit like a tall building designed to withstand an earthquake where they put the water tank on the roof - so that when the building sways, the water is going in the opposite direction at the same frequency."
With the use of mass dampers growing, however, the FIA this week stepped into the situation and outlawed them completely.
With the damper systems helping improve handling characteristics through corners and over kerbs by keeping the car more level, the FIA has claimed that the devices are illegal because they are 'moveable aerodynamic devices'.
A letter sent to the teams by FIA technical delegate Charlie Whiting said: "The use of mass dampers, normally fitted in the nose of a car, is now widespread. Even though we have never been asked specifically whether or not their use may contravene any part of the Technical Regulations our view, until now, has been that they do not.
"However, recent evidence and an escalation in development by some teams, has made it clear to us that the principle purpose of these devices is to improve the aerodynamic performance of the car.
"As the mass suspended inside the dampers is designed to move freely it is therefore not secured to the entirely sprung part of the car nor does it remain immobile in relation to it.
"Therefore, as this movement influences the aerodynamic performance of the car we feel that mass dampers of this sort contravene Article 3.15 of the F1 Technical Regulations and we no longer consider their use permissible."