In 2021, Formula 1 will race with 18-inch wheel rims, up from the current specification of 13-inch. The tests with the new wheels are in full swing because they will be part of F2 from next season.
Formula 2 in 2020 will serve extra data for Pirelli as they're desperate to get the tyres right for the regulation overhaul. The tyres this season are a major talking point, something Pirelli won't want come 2021.
At the end of the 2019 season, Formula 1 teams will have the opportunity to use the new wheels. But just recently in Italy, Pirelli put the new wheels on a Formula 2 car and released these images.