F1 to adopt 18-inch tires starting in 2021 season

Paris – Formula 1 racing will move to 18-inch rim diameter tires and wheel, starting with the 2021 season, according to the Federation International de l'Automobile's tire supply tender offer for the 2020-23 seasons.

The deadline for interested companies to submit an offer is Aug. 31, the FIA said. The tender offer calls for the continuation of a single-supplier relationship.

Pirelli Tyre SpA has been Formula 1's designated race tire supplier for the past eight seasons and has the contract through 2019. It first proposed moving to 18-inch tires in 2014 and has been testing prototypes since.

The current tire specification calls for 13-inch tires, and the tender offer specifies that will continue to be the size for the 2020 season. The offer calls for the change to 18-inch tires — 270/18 front and 405/18 rear — for the 2021-23 seasons. The overall outside diameter is listed as between 700 and 720 mm.

The tender also calls for the elimination of warming blankets for the tires. These are used by the teams to warm the tires up before mounting them on the cars during pit stops in order to minimise the amount of time their drivers need to get the tires up to optimum operating temperatures.

The FIA said it expects to decide as to the technical and safety requirements by 14 Sept. All tenders that meet the FIA's technical and safety requirements will be submitted to the commercial rights holder of the F1 championship, which then will conduct commercial negotiations with each approved bidder and make the final selection of the entity it proposes to be appointed by the FIA.

The FIA's tender calls for the next tire supplier to continue the practice of providing three different compounds tires at each race as part of the series' drive for enhancing competition.

Taking into account the nature of each circuit visited, the tender proscribes performance and degradation characteristics as follows:

Hard compound: 2- second lap time degradation achieved at 22% race distance;

Medium compound: 2-second lap time degradation achieved at 18% race distance; and

Soft compound: 2-second lap time degradation achieved at 10% race distance

The intent is to create the maximum number of race strategies yielding race times such that multistep strategies provide just enough potential of a beneficial outcome to encourage the greatest variety in the racing spectacle, the FIA said.

Pirelli uses coloured sidewalls to distinguish the different tire types.