Montmeló (Spain) (AFP)

Six pole positions and five victories since 2014: in Spain, on the Barcelona-Catalonia circuit, Mercedes still advance as the favorite ... but the last two Formula 1 Grands Prix have revealed the weaknesses of the six-time champion team. world.

The Spanish round will also see the return to the track of Mexican Sergio Pérez (Racing Point), who finally tested negative for the new coronavirus after two weeks of forced absence and "slight symptoms" which did not prevent him from training.

This season, it took five races - again and still behind closed doors - to see someone other than Lewis Hamilton or Valtteri Bottas on the top of the podium.

That other is Max Verstappen, whose Red Bull raced to victory at the 70-year-old F1 GP at Silverstone (Great Britain) last week, as the Silver Arrows had to slow down due to tires. blistered by heat.

The previous week, already at Silverstone for the British GP, the Briton had scared himself by winning on three wheels after a puncture at the end of a too long stint, when Bottas found himself relegated out of the points at the following a similar mishap.

"It shows that Mercedes can be vulnerable if you put pressure on them and that is what we have to do regularly," urges Red Bull leader Christian Horner.

The only driver to have scored points in all races, Hamilton nevertheless has a comfortable lead in the world championship: 30 lengths over the Dutchman, second, and 34 over his Finnish teammate, third. Among manufacturers, Mercedes, it has a margin of 67 points on its Austrian rival.

- "Good direction" -

The Barcelona circuit is also demanding on the tires and the temperatures will still be hot this weekend (30 degrees in the air, 50 on the track). "A good thing !" for Verstappen.

"We have taken advantage of the last few days to understand the problem and find ways to solve it in the future," said Mercedes team principal Toto Wolff. "Our level of performance looks better when it's a little cooler, so the heat is going to make things more complicated, but we can't wait to get back on track to see if we've moved in the right direction."

For this, "the guys have worked hard" since Sunday, adds Hamilton, despite fatigue and weariness, this GP being the third in as many weeks.

Another peculiarity of the Catalan layout is where F1 carries out its pre-season testing. "So we can go back and compare our performance, what we achieved in February and what we are achieving today," said Haas team principal Günther Steiner.

Even contested in August rather than May, delayed by the coronavirus pandemic, the Spanish GP therefore remains conducive to a progress report.

Off-piste, participants were recommended to limit their travel between the circuit and their accommodation, in a region, Catalonia, particularly affected by the Covid-19.

After Pérez, but also the French Gabriel Aubry, tested positive ahead of the 6 Hours of Spa-Francorchamps (Belgium), round of resumption of the World Endurance Championship (WEC) on Saturday, caution is more than ever in order.

© 2020 AFP