@Koushik: Alonso has been in the puts for the last 20 minutes or so. The car has had no new problems the team has reported, but they have been muddling through without a new solution for the MGU-K issue they had yesterday. That is arriving at the track in time for tomorrow's session.
On the point of Alonso, I've just got back from a press conference with Boullier and Arai and they say McLaren is 50% behind schedule because of yesterday's MGU-K setback, so expect to see Button and Alonso doing as many laps as possible over the weekend.
@Scuderia: Wishful thinking, I know. We will only have 18 cars if Marussia don't make the grid this year - no third cars.
The usual flurry of activity at the end of the day has begun. Ricciardo, Raikkonen, Perez, Alonso and Palmer are on track.
@Koushik: Red Bull have had a good day today, but it's the first time this year they have got anywhere near that kind of mileage. Mercedes still has the most from today when you combine Rosberg and Hamilton, which is in step with the rest of testing so far.
As he has been for most of the day, Perez is circling out there on a set of super soft tyres. Alonso is on mediums, while Palmer is driving in the winter tyre especially designated for testing.
Ten minutes to go of the second day - lap times updated so you can compare mileage as we approach the chequered flag.
@Scuderia: The last 18 car grid was at the US and Brazilian GPs last year. Before that it was the 2005 Monaco GP when BAR were banned but there was also a 6-car grid that year at the US GP when Michelin withdrew the cars it was running.
@sumanth: Not having a car at the first two tests is not a good start. I imagine Lotus will hope to be back ahead of the Force India this year.
Hamilton is out on track on the super-soft tyres, could this be a new fastest lap?
@Spike: Not exactly, but definitely nowhere near 100%. We won't see that until next week's test.
Ooops, we need to get our eyes checked. Turned out that was the orange hard tyres not the red super-softs on Hamilton's car.
Definitely a trip to Specsavers for me when I get back to the UK.
@Mikemartz: They'll stick around as there is only three days off between. But expect to see even more new parts and updates on the car next week.
Chequered flag out - that's the end of day two of the second test.
Full time update and report to come
Ricciardo remains on top with the fastest time we have seen at this track in an F1 car since 2013.
Thanks for joining us today. We'll be back with more live commentary over the weekend and Nate has just been sent to the paddock to gather all the reaction to today's test. Stay tuned on espnf1.com for more news