The next single supplier contract will cover the four seasons from 2020 to 2023, the first of which will be run with current tyre sizes and blankets.

From 2021, the front tyres are set to be narrower, dropping by 35mm to 270mm. The rears will stay the same, at 405mm, while diameters will increase from the current 670m to “700-720mm.” 

That means if anyone other than Pirelli wins the bid, it will have to develop tyres from scratch that will be used for only one year before the major package of rules changes comes on stream in 2021.

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That will clearly make it very difficult for someone like Michelin – which wanted F1 to switch to low profile tyres when the last bid process took place.

The loss of tyre blankets will be one of the biggest technical challenges that the winning bidder will face.

The subject has been discussed and attempts have been made to introduce it, but the plans were always canned on safety grounds.

The FIA has noted, however, that it believes there is a way forward that will not require a change of heart this time.

"Tyres should provide safe performance when leaving the pits cold," said the official FIA tender document.

"The glass transition temperature must be chosen so that the tyres are never in a ‘glassy state’ when either the ambient or the track temperature is above 10 degrees centigrade.”

Intriguingly it adds that “for winter testing a specific low temperature tyre will be required. This will form the bulk of supply to the teams for European winter testing with a limited number of race compounds available,” while confirming that “wet and intermediate tyres should also be capable of running without the need for pre-heating.”

The FIA makes it clear that the “improvement of the show” is a the number one priority, and that the process should start with the final year of the current tyre sizes: “The provider should commit to achieving this in 75 percent of circuits in 2020, and to improve their performance with respect to this objective throughout the whole period of the tyre supply.”

In addition, “in order to stabilise at a pressure that provides peak performance, the tyres must be capable of commencing running at cold pressures compatible with achieving suitable stabilised pressures.”

There will be three compounds at each race, as expected, with the simplified hard, medium and soft names. The FIA characterises the tyres as follows:

- Hard compound: 2s degradation achieved at 22% race distance Base lap time

- Medium compound: 2s degradation achieved at 18% race distance 1.2s/lap quicker than Hard compound

- Soft compound: 2s degradation achieved at 10% race distance 2.2s/lap quicker than Hard compound

The FIA hopes that there will be more strategic variety, saying that “the intent is to create the maximum number of race strategies yielding race times such that multi-stop strategies provide just enough potential of a beneficial outcome to encourage the greatest variety in the racing spectacle.”

For a typical circuit it wants the following:

- 1x Medium Compound + 1x Hard Compound = 1-Stop Race

- 1x Soft Compound + 2x Medium Compound = 2-Stop Race

- 3x Soft Compound + 1x Medium Compound = 3-Stop Race

Regarding tyre wear, the FIA says it is “considered desirable both for its impact on race strategies and to ensure tyres are not run to a point of excessive wear. A non-linear performance gradient change (‘cliff’) at a certain percentage of tyre wear would achieve this. It is suggested that an underlayer of low performance is designed below the tread compound to achieve this.”

The FIA also wants tyres that can recover, noting “it is expected that aggressive driving or close following will incur higher tyre degradation per lap than gentle driving or driving in free air. Once a period of aggressive driving or close following ceases, the tyre should rapidly recover the lower level of degradation per lap associated with the more benign conditions.”

On the matter of performance it adds: “In terms of absolute lap time, the performance of the tyres fitted to 18” wheels should, when at operating temperature, be at least as good as the 2019 tyres.”

Tyre suppliers have until August 31 to submit their bids. A decision on technical and safety compliance will be made by September 14, and then after the commercial aspects of any ‘Approved Bidders’ will be considered.

Liberty will then make its choice, which then has to propose prior to official approval by the FIA.