Ferrari pair Kimi Raikkonen and Sebastian Vettel led the way at the end of the second session, with Mercedes half a second adrift of its main opposition.

But rather than be concerned about what appears to be a big deficit, Mercedes boss Toto Wolff said his team was quite relaxed because of the power modes that his team understands Ferrari was using.

“They were in a pretty high-power mode when they were on the lap, so it isn’t so worrying, but it is a good lap,” Wolff told Sky.

“And what we have seen in Melbourne and again here is that at various stages the teams are close together, so I can’t really judge.”

When asked about why he was confident that Ferrari was using high power modes, he said: “It’s quite amazing. We have GPS data, so you can follow the traces of every car.

“You can see that when you overlay the data, suddenly on the straights they gain much more time, and in the corners it’s still the same.

"You can see that in detail, so it’s become very transparent for the engineers how much somebody has turned up the power, and how much downforce, and how much drag everyone is running.”

There was a lot of focus on Mercedes’ engine modes at the Australian Grand Prix in the wake of Lewis Hamilton’s dominant pole position, but the indications are that there is very little to choose between the performance of the German car manufacturer and Ferrari.

Lewis Hamilton said in Bahrain on Thursday: “They said in qualifying we think that we are power-wise equal to them. They made a really big improvement. And [the team said] that in the race we might have a slight edge on them.

"It's hard to say from one race, they had a different run profile, particularly in the race they were doing something different fuelling-wise.

"You'll get a much better idea over the coming races."