A rumor has begun to gather momentum in the Formula 1 paddock of McLaren using a mechanic adjustable rear brake duct, which alters the heat going into the tyre via the wheel. The device could be providing the Woking based team with a legal way to manage their tyre temperatures during a race weekend.

During pre-season testing, the device was first spotted and has been supposedly used since the Chinese Grand Prix after McLaren suffered with tyre temperature issues in the wet race in Malaysia. The device works by a mechanic adjusting the brake duct opening around the disc which in turn sends more heat through the wheel, thus increasing the temperature of the tyre.

It is currently unknown as to whether this device is present on any of the other cars on the grid. The device isn’t classified as ‘moveable aero’, and therefore is considered legal as it is believed the device isn’t adjusted during the race.

In a season which has been heavily dictated by the Pirelli tyres so far, this device could well begin to be copied up and down the grid. With a three-day test at Mugello starting today, it’ll be interesting to see whether the device is used and whether any of the other teams introduce a similar device as they prepare for the beginning the European leg of the season.