Pirelli started track testing its new 18-inch tyres at Paul Ricard on Thursday, releasing a short video of what the new rubber looks like on an F1 car.
The Italian manufacturer is putting the 2021-spec tyres through their paces during thsi week's two-day test, using a mule car supplied by Renault and entrusted to reserve driver Sergey Sirotkin.
The Russian will share the track with Mercedes reserve driver Esteban Ocon, although the Frenchman will devote his time to Pirelli's 2020 tyres.
— Pirelli Motorsport (@pirellisport) September 12, 2019
"It is the real first test with 18-inches tyres in a modified car, a new car," said Pirelli motorsport boss Mario Isola, quoted by RaceFans.net.
"So everything is new and there is a lot of question marks. But it’s important for us to start in September because at least we have time to react if we find any behaviour that was not predicted by our simulation."
Sirotkin added: "It will be something, new, something interesting and we are all very excited about it."
While the new specification tyre will make its entry into F1 in 2021, the FIA Formula 2 Championship will rely on 18-inch wheels as soon as next year.
In addition to Renault, McLaren and Mercedes will also supply mule cars to Pirelli's development programme which will continue at Paul Ricard with the Woking-based outfit in October, and with the Silver Arrows squad in December.