@ENGonzaga: I think Rosberg's time from yesterday showed the kind of advantage they held. Of course, translating lap time from a cold Barcelona during testing to a much warmer (I hope) Albert Park is not an exact science. Nevertheless, it seems Mercedes has a healthy margin over the rest of the field at the moment.
@Efranov: Teams always run installation laps and systems checks at the start of a GP weekend anyway.
@Khalid@dxb: That statement needs a few clarifications. First, Rosberg was on the soft tyres and Hamilton was on the mediums for his pole lap last year. Secondly, the cars at the Spanish Grand Prix were probably somewhere in the region of a second slower than the ones that left Abu Dhabi at the end of the year. Third, track conditions were different and we don't know if Rosberg was on qualifying fuel.
As for how they will compare to 2004, I think the tyres and power units will be limiting factors. A better target is the 2013 cars. Rosberg managed a 1:20.130 at this test two years ago in the Mercedes W04, so there is still some way to go.
@AbhishekChoudhury: I haven't seen any mark in any of the photos we have access to or I've seen published elsewhere. McLaren has given a perfectly feasible reason for the accident (a lot more believable that the accounts elsewhere on the internet) and there is no reason to think they are hiding something.
Hamilton has set the pace so far with a 1:26.110 on the medium tyres. 20 laps completed for the Mercedes so far and it's back in the pits.
Alonso's was nastily shaken because the car took the load as a side impact through the suspension. The angle meant the wishbones didn't come off and dissipate the impact, instead the whole chassis - and Alonso inside it - felt the full force of the impact, which was reported by the BBC to be at 135mph. Vettel has now clarified his remarks, saying he only saw the end of the accident after the initial impact. There is nothing unusual about a car running wide on AstroTurf and losing control, it's just unlucky he got spat towards the inside barrier at that particular angle. Otherwise we wouldn't be having the conversation.
On track now are Ricciardo on the mediums and Hulkenberg on the super-softs as well as the McLaren - now on its third lap on mediums.
@Patz: Yep, the teams work on the cars all through the night. Most teams have a day crew of mechanics and engineers and a night crew working in shifts.
@mike: Yes, the cars are now fitted with titanium skidblocks on the floor that create sparks. I think the sound has been slightly improved - they sound cleaner and crisper. The Honda definitely seems a bit louder, but I'm not convinced they are that much louder than last year.
@Romain: McLaren has said that won't happen from what I understand.
@BC: There was a theory that it was running without an MGU-K early in testing so sounded different, but I think it's more down to the engine itself and exhaust.
@Ventana: A 22 laps and sit around in the pits simulation. Typically teams do a bit of running (a bit like an FP3 session) to check a few things before attempting a qualifying sim before lunch and a race sim in the afternoon.
@Prithvi: The car is impressively reliable for this stage of testing. 23 laps completed today to add to the 77 laps yesterday afternoon. 100 in total.
@JanVisser: The engines are broken down to six components: the engine (ICE), the motor generator unit-kinetic (MGU-K), the motor generator unit-heat (MGU-H), the energy store (ES), turbocharger (TC) and control electronics (CE). If a car uses more than four of any of those components over the course of the year it will get a 10-place grid penalty for the next qualifying session.
@shailesh: Hulkenberg's best on the super-soft is a 1:29.449, so he wasn't going for a quick lap - more likely just running a few early tests.
@AdiosAyrton: He's set the quicker laps, but one quick lap on the softs can be quite misleading. Hamilton hasn't used the softs yet, so it will be interesting to see if he gets a chance today. Even then, however, track conditions change from one day to the next, so we won't get an accurate comparison between the two until Australia
@JanVisser: Each car may use no more than one gearbox for six consecutive races with a five-place penalty if it fails to do so. The only change to the gearbox regs is that they can no longer change the ratios once during the season - they have to stick with what they start with.
@DesiSongsVIDEOS.: No, the teams are not allowed to test a current car outside of the official tests. It's quite hard to test an F1 car without someone noticing it, but Mercedes did manage in 2013 when they conducted a "secret" tyre test with Pirelli in that year's car. That kicked off a massive argument over whether they should have been doing it and Mercedes was banned from the next in-season young driver test that year.
@JonnyDietrick: Teams could try to test, but there is always a danger that someone - at the track, within the team or at Pirelli (they would need tyres after all) - leaks the news. The Pirelli test was a contentious one because of the agreement between Pirelli and the FIA being a bit of a grey area.