Paris, France - McLaren's Lando Norris set the fastest time while George Russell made his Mercedes for the debut in two days of testing on next season's bigger Pirelli tyres in Abu Dhabi.
Norris drove 103 laps over on Tuesday and Wednesday, including a best time of 1min 25.809sec, which he set on the softest of the five compounds available.
Fellow Briton Russell completed 214 laps at the Yas Marina circuits and was fourth fastest.
Daniel Ricciardo was second fastest in the other McLaren with Sebastian Vettel third his Aston Martin.
The newly-crowned world champion Max Verstappen drove on Tuesday for Red Bull. His best time only placed him 16th among the 19 drivers who took part.
His British rival Lewis Hamilton of Mercedes, who is not very fond of this type of testing, was absent. He went to Windsor Castle near London on Wednesday to be knighted.
Verstappen was also in England on Wednesday, returning to the Red Bull team base in Milton Keynes for a team celebration.
Finn Valtteri Bottas, whom Russell is replacing at Mercedes, made his first appearance for his new team, Alfa Romeo.
Bottas outpaced his future teammate Guanyu Zhou, who will become the first Chinese driver to start a Grand Prix next year.
Brazilian Pietro Fittipaldi, the grandson of former champion Emerson Fittipaldi, drove for Haas in place of Russian driver Nikita Mazepin, who tested positive for Covid-19 last weekend.
The only team not to participate was Williams.
The tests, which were intended to give the teams data to work with during the off-season, were conducted on cars adapted to the increased diameter of the wheels from 13 inches to 18 inches.
The cars, however, were not yet the ones that will take to the track next year, after a major change in the technical regulations.
"We are happy with the tires as it is. We are not planning to make any changes. We know some details we'll need to fine tune/adjust when we start using the new cars," Pirelli's head of racing Mario Isola told a virtual press briefing on Wednesday.
Further days of testing, which will allow for "fine-tuning", are planned for next year.
Pirelli said in a statement that their simulations suggest "the new cars will be around five tenths of a second slower than the current cars".
But Isola said he believes that this will be quickly erased because of the "big potential of development" for the 2022 cars.
Alongside the tests of next season's tyres, the traditional post-season tests for young drivers were run in this year's cars and were dominated by Dutchman Nyck de Vries, a reserve driver for Mercedes and the Formula E world champion.