FIA issues detailed F1 tyre pressure and temperature guidelines

Mercedes was investigated after the race at Monza after tyre pressures on the left-rear of the cars driven by both Lewis Hamilton and Nico Rosberg were found to be below the recommended minimum limits set by Pirelli.

The race-winning team, though, was cleared by the stewards due to extenuating circumstances regarding the timing of the measurement and how long the tyres had been out of their warming blankets.

The stewards suggested Pirelli and the FIA "hold further meetings to provide clear guidance to the teams on measurement protocols".

That resulted in an agreement between the tyre manufacturer and governing body on the format regarding tyre pressure readings.

Pirelli has further informed the FIA its tyres may only be operated safely if the prescriptions set out in its preview document for each race are strictly followed.

To that end the FIA will enforce the following parameters regarding the minimum starting tyre pressures front and rear:

1. During all practice sessions and qualifying, it will be the pressure measured immediately after the set of tyres in question is fitted to the car.

2. The race-start set will be measured at any time after the five-minute signal.

3. During the race it will be the pressure measured immediately before the set of tyres in question is fitted to the car.

In all cases:

4. When measured, the pressure must be equal to or higher than the minimum set out in the preview. If the pressure is below the minimum requirement teams will be given the opportunity to increase it, however, at no time after the five-minute signal may pressures in the race-start set be reduced.

5. Measurements may be taken from any corner of the car.

6. Measurements must be made with a gauge calibrated at, or by, Pirelli, and subsequently sealed by the FIA.

7. After the checks have been carried out, and any necessary adjustment made in the presence of a scrutineer, no further adjustments may be made.

With regard to the maximum tyre temperatures in the blankets, they will be checked by an infra-red gun as before.

These checks will be made both on the tread and sidewall of the tyre, and when measured must be equal to, or lower than, the maximum set out in the preview.