Mercedes and Racing Point had to change the rear suspension detail at the last minute because of the position of the rear brake cooling intakes that Red Bull protested ​​in Melbourne.

The current world champions had to take 'countermeasures' to address the reliability issues they experienced in pre-season testing.

The current world champions dominated this year's tests with the best times, the most exciting innovation and the most laps, but other teams had very good preparations, with nine of them driving more than 80% Mercedes' laps.

The world champions have confirmed that Lewis Hamilton stopped on the track due to engine problems, which limited his running to only 14 laps, and Mercedes had the worst day of the season with only 61 laps.

Sebastian Vettel stayed fastest by the end of the second day of the second Barcelona test after setting best time for Ferrari this year while Lewis Hamilton completed only 14 laps in the afternoon before he was hit with engine problems.

Mercedes is by all accounts the winner after the first test in Barcelona, ​​but it is enough to remember 2019 and the wrong conclusion that followed after the first test to wait at least the second test for all teams to do real qualifying simulations.

Watch the comparison of the fastest lap at this year's Barcelona Tests and last year's pole position, which is still a track record - both laps were driven by Bottas and last year's lap is 0.326 s faster.

In its review of the first three days of testing, Mercedes said that they could not accurately predict the performance levels of their rivals based on the available data, but added that Ferrari did not use the same engine power as their customers Alfa Romeo and Haas.

Lewis Hamilton and Valtteri Bottas are delighted with the reliability and speed of the new Mercedes F1 car for 2020, setting the two fastest laps in Barcelona's first preseason test, as well as completing the most laps as a team.

Valtteri Bottas set the fastest lap on the last day of Barcelona's first test, 1.5 seconds faster than the fastest time so far this year and only three tenths slower than the track record while Ferrari had a problem with the engine which needed to be replaced.