Lewis Hamilton upped the ante with team-mate Nico Rosberg leading the second practice session at the British Grand Prix.
After Rosberg had led in the morning, Hamilton responded to go quickest in the afternoon when the faster option tyres were used for the first time.
It wasn't all plain sailing, however, as the No. 44 Mercedes pulled off the track with half an hour to go as the engine cut out in his W05.
The German's session was trouble free, however, and he would take second behind Hamilton with Fernando Alonso again third for Ferrari.
Can Red Bull challenge Mercedes?
The picture at the front is slightly distorted, however, as Red Bull appear to have the pace to potentially challenge Mercedes, certainly if the forecast rain hits on Saturday.
Daniel Ricciardo was fourth quickest but his best time, albeit a second off Hamilton, was on the prime tyre therefore on the softer medium compound the Australian could realistically find another eight tenths as most drivers around him did.
But it wasn't a smooth afternoon neither for the just turned 25-year-old as he was a problem of some kind forced Ricciardo to end his session early without completing an important race simulation.
If he can match the pace of his team-mate Sebastian Vettel, however, then maybe both RB10's could be battling the Silver Arrows on Sunday.
With Hamilton and Ricciardo sidelined, the two Germans were posting near identical lap-times throughout the 20 laps on the white-striped medium tyres.
Also in Red Bull's favour could be tyre wear as the Adrian Newey-designed car is thought to be kinder on the Pirelli's than the Mercedes.
If that is the case a one-stop strategy could be possible in a normal dry race while Mercedes have have to do two.
Behind the top five the midfield battle remained as close as ever.
After a disastrous morning Williams made up for lost time and Valtteri Bottas was sixth quickest, but the Finn had to deal with a strange problem as his engine cover appeared to 'pop' under pressure at high speed near the end of the session.
Better news for McLaren
Better news for McLaren fans as the team continued to look strong in the afternoon. Both cars again made it into the top 10 ahead of Ferrari's Kimi Raikkonen who appeared to lack traction in the F14-T.
Jean-Eric Vergne also made his second appearance in the top ten for Toro Rosso though his practice was cut short by a wheel failure.
There was a better showing for Sauber's Esteban Gutierrez in 13th, however, the disappointments of the day belong to Lotus and Force India.
For a car known to enjoy more aero-dependent tracks, Lotus remained nowhere with Romain Grosjean proclaimed the car was "really bad" over the radio.
While Force India are the nearest team to Silverstone, located about 400 yards from the circuit, they too struggled in the windy conditions.
At the end of the day Grosjean and Pastor Maldonado held 14th and 15th with Force India's driver just behind in 16th and 17th.
There were more mechanical issues at Marussia as Jules Bianchi was hampered by a turbo issue, but the Frenchman was still best of the slower teams as Kamui Kobayashi again pipped Max Chilton in the Caterham with Marcus Ericsson again bringing up the rear.
At the front, however, and there is a very interesting sub-plot potentially with both Daniel Ricciardo officially under investigation for overtaking during the red flag period in FP1.
A pit-lane source told Sky F1's David Croft no further action would be taken on the matter though we will wait for confirmation.
Should that be the case then the Hamilton vs Rosberg battle is shaping up to be as close as ever, with honours even on Friday it may come down to who can master the wet should the forecast rain hit on Saturday.
If so, that would favour Hamilton in my opinion but could also bring the Red Bull's more into play remembering what Ricciardo did in Australia, Malaysia and China.
Fasten your seat-belts this is going to be one hell of a weekend ride.
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