Ahead of today's sole free practice session, the air temperature is 28 degrees C, whilst the track temperature is 42 degrees. It's bright but once again there is a strong breeze.

As expected, Mercedes led the way yesterday with Nico Rosberg quickest in both session but Lewis Hamilton always within 0.1s. However, also as expected, it was the group(s) behind where the real competition lay.

Though the Ferraris were third and fourth, Williams, where Felipe Massa was side-lined in FP2 following a water leak which necessitated the power unit being removed, didn't seem unduly concerned. However, the long run pace of the Maranello cars was particularly impressive.

It was a mixed day for Red Bull also, Daniel Ricciardo sitting out the second session as the team changed his engine. More worrying is the fact that the Australian has already used one (of his four) power units for the season.

In both cases, with one driver restricted to the role of spectator, his teammate did the business.

The big surprise is Toro Rosso where both drivers (and the car) looked impressive, though Max Verstappen lost much of FP2 due to a sensor issue.

Lotus and Force India were next up, the Silverstone team still getting to grips with its brand new car, whilst it's fair to say that Sauber had other things on its mind.

McLaren endured another difficult day, Kevin Magnussen crashing out following a mistake in FP2, whilst Jenson Button's best lap was 3.6s off the pace.

Due to a number of issues, Marussia was a no-show, neither driver even getting into the car though the team did issue a post-session press release as though they had.

So, no major surprises, unless you consider the competitiveness of the Toro Rossos, and lap times are up by a couple of miles per hour.

However, today, especially in qualifying, and even the end of this session, is when we should get an idea of the true form.

The tyre compounds are medium and soft, whilst there are two DRS zones, detection is 13m before T14 with activation 30m after T16 and 32m after T2.

The lights go green and Bottas leads the way, followed by Vettel, however, the German quickly overtakes the Finn. Maldonado, Ericsson, Grosjean and Nasr among the early risers.

Meanwhile, Manor reveals: "FP3 time but sadly we haven't toppled all our challenges yet. Good progress in past 24 hrs though & we are of course still plugging away." Which begs the question, why exactly are they here then? Sorry, but there's something wrong here.

Kvyat is unhappy with his engine, he claims that it feels as though it is pushing him under braking. He subsequently goes off at T15 before returning to the pits.

The Sauber duo, the Van der Garde legal case on hold for now, post the first times of the day, Nasr (33.301) and Ericsson (33.851).

Ten minutes into the session and all but Ricciardo have been out.

As Ericsson runs wide, Ricciardo reports that his engine is "patchy". No such problems for Rosberg who, when asked if everything is OK with his car, replies: "All ok, thanks".

Sainz posts 31.755 to go quickest, with Ricciardo going third (32.565) moments later.

Maldonado runs very wide in T9 but continues, the Venezuelan subsequently posting 32.460 to go fourth.

Verstappen's car bouncing around sending up a shower of sparks - a noticeable, welcome return to the sport this year. Sparks that is.

A 31.060 sees Grosjean go quickest, ahead of Verstappen, Maldonado, Sainz and Nasr, with only four other drivers having posted times.

Raikkonen is the first of the big guns to come out for what looks to be a time-posting lap. Not a quick run from the Finn (41.694) which suggests he's collecting data.

As Rosberg begins his first flying lap, Raikkonen goes quickest in S1. The German crosses the line at 32.115 to go sixth, whilst the Finn goes quickest with a 30.283.

Next time around Rosberg goes quickest in all three sectors, stopping the clock at 29.364.

Oh dear, Ricciardo has ground to a halt just after leaving the pitlane. "I'm going to jump out," he says. "Stay there," he is told, "the guys are coming to get you."

Meanwhile, Bottas goes second (30.004) and Vettel third (30.159).

As Ricciardo is pushed backwards into the pitlane, he gets in the way of a Sauber driver looking to perform a practice start.