Pirelli is on the lookout for a F1 test car.
The Italian company has secured the contract to remain in F1 beyond 2021, when the rim profile will go from 13 to 18 inches.
"One of the biggest problems at the moment is to find a suitable test car," Pirelli's Mario Isola admitted to the Dutch publication Formule 1.
"The basis will be a car from 2018 but with adapted suspension and aerodynamics to be representative of what we can expect in 2021," he said.
"But as the technical regulations for 2021 have not yet been laid down, the teams don't know what to deliver."
Nonetheless, Isola said Pirelli wants to start testing the 18 inch tyres from September.
