Horner: FIA had no choice over dampers

Champions Renault were told last month that the system they had been using since September to level out tyre vibrations was, in fact, against regulations.

On Wednesday, that decision by the governing body - initially over-ruled by race stewards - was upheld.

Renault, just seven points clear of Ferrari, must now complete the last five Grands Prix without a device credited with cutting at least 0.2 seconds off their car's laptimes.

Horner, whose team had also experimented with the dampers, believes Renault were lucky enough to have run it for so long.

"If you potentially allow it in one area, where else are they going to go? In the fuel cell, in the gearbox? They could end up appearing all over the car," Horner said.

"I think that the decision they came up with was probably ultimately the only one that they could realistically take.

"It was always on thin ice and Renault have probably done pretty well to have run it for as long as they have."