Lewis Hamilton ended the first pre-season test fastest – but his Mercedes team-mate George Russell warned not to take the lap times too seriously.
Seven-time world champion Hamilton set his best time late on the final day of the three-day stint in Barcelona – supplanting Russell, who had set the pace in the morning session.
Hamilton and Russell headed Red Bull duo Sergio Perez and Max Verstappen.
Russell said: “Lap time-wise, I don’t think it’s representative at all.”
He added that Ferrari and McLaren were “looking incredibly strong”.
“Even though we are top of the timesheets, I wouldn’t read too much into it,” said Russell.
“We have some improvements to make, as we’re not fully happy with the balance of the car and the limitations we have currently. But we have a good indication of the direction we need to go in.”
Hamilton was 0.095 seconds quicker than Russell as both set their fastest times on the softest tyre compound available.
And Hamilton was only 0.003secs off his best time using tyres one grade harder, and therefore theoretically significantly slower.
Perez was 0.418secs behind Hamilton’s best on the same type of tyre, while Verstappen was 0.618secs off the pace on tyres two grades harder than the man he beat to last year’s title in the controversial decider in Abu Dhabi.
Hamilton said: “It’s been an interesting few days. It’s not been the easiest or smoothest running. We have had some obstacles to overcome.
“We would always want more laps but I am happy with today – we have had 100 laps, which for a half-day wasn’t too bad.”
Asked whether he had an idea where the team were in terms of competitiveness, Hamilton said: “You never do on the first week. We have no idea where we are.”
Aston Martin’s Sebastian Vettel was fifth fastest, on the softest tyre, ahead of Ferrari’s Charles Leclerc, on the same tyre as Verstappen.
McLaren’s Lando Norris, fastest on the first day of the test, was 11th quickest on Friday.
He said: “It has been a decent start. If there is any team we expect to be at the front when it matters, it is going to be Mercedes and probably Red Bull.
“I don’t think we’re in an amazing place. We are in a good place. The car worked well as soon as we put it on the track.”
Headline lap times in pre-season testing are notoriously unreliable as indictors of true competitiveness as fuel loads, engine modes, track conditions and other factors can all have a dramatic effect on performance.
Alpine, Aston Martin and Haas all had to curtail their testing before the end of the day after suffering leaks in the morning session that meant they could not repair their cars in time to run again.
Pierre Gasly crashed the Alpha Tauri before lunch and the team were unable to repair it in time for Yuki Tsunoda to go out in the afternoon.
Among Mercedes’ problems was a strange high-frequency “bouncing” phenomenon on the straights, which is affecting all the teams to one degree or another.
This is created by the new aerodynamic philosophy inherent in cars designed to new regulations that are aimed at closing up the field and making the racing more competitive and amount to the biggest technical change in 40 years.
The problem – also known as ‘porpoising’ – is caused by the airflow under the cars being disrupted above a certain speed on the straights.
The cars sink towards the track because the downforce load increases as the speed increases. As the ride-height reduces, it gets to a point where the airflow is disrupted, which leads to a loss of downforce. The car jumps up and then, when the airflow reforms, begins to sink back down, until it is disrupted again at the same point.
Ferrari’s Carlos Sainz, seventh fastest on the final day, said: “It doesn’t feel great.
“We’re doing 300km/h and jumping 30-40mm up and down. Annoying. Hopefully it’s resolved and it’s not something we need to live with because it’s quite on the limit.
“You have to trust the engineers that it is going to keep getting better as we learn the ground-effect cars.”
What were the drivers’ fastest times on Friday?
1 Lewis Hamilton (GB) Mercedes one minute 19.138 seconds **
2 George Russell (GB) Mercedes, 1:19.233s **
3 Sergio Perez (Mex) Red Bull 1:19.556s *
4 Max Verstappen (Ned) Red Bull 1m19.756
5 Sebastian Vettel (Ger) Aston Martin 1:19.824 **
6 Charles Leclerc (Mon) Ferrari 1:19.831
7 Carlos Sainz (Spa) Ferrari 1:20.072
8 Alex Albon (Tha) Williams 1:20.318 *
9 Nicholas Latifi (Can) Williams 1:20.699 *
10 Daniel Ricciardo (Aus) McLaren 1:20.750
11 Lando Norris (GB) McLaren 1:20.827
12 Fernando Alonso (Spa) Alpine 1:21.242
13 Guanyu Zhou (Chi) Alfa Romeo 1:21.939
14 Pierre Gasly (Fra) Alpha Tauri 11:22.469 *
15 Nikita Mazepin (Rus) Haas 1:26.229
16 Valtteri Bottas (Fin) Alfa Romeo 1:30.433
** = time set on C5 tyre, the softest; * = C4 tyre; all other times set on C3.
