Mercedes, McLaren and Renault to begin 18-inch tyre testing

Pirelli Formula 1 chief Mario Isola has confirmed that Mercedes, McLaren and Renault have agreed to supply a mule test car to commence testing for its 18-inch wheels later this year ahead of their introduction in 2021.

F1 will make the switch to 18-inch wheels as part of the planned overhaul of the technical regulations in 2021, with Pirelli continuing as the sport's sole tyre supplier until at least the end of 2023.

Speaking on Friday in Spain, Isola outlined the early details for Pirelli's testing programme ahead of the switch, which will commence later this year.

"The intention is to have three sessions – September, October and November – and three teams are going to supply the mule car, and they are Mercedes, McLaren and Renault," Isola said.

"We are going to offer the opportunity to provide a mule car for 2020 again to all the teams. It’s their choice if they want to do that or not. So it’s the same system and the same procedure that we have used in the last few years. We offer to everybody, teams can accept or not and then we make a plan according to the number of teams that accept it.

"We have 25 days of testing for next year, as it was in the last few years. We have a short development plan for 2020 in the first half of the season and then we switch on 18-inch tyres from September onwards."

Pirelli confirmed earlier this week that Formula 2 would be switching to 18-inch tyres next year, acting as a test bench for the Italian manufacturer ahead of F1's switch the following year.