All signs may point to another season of Mercedes dominance, but it was far from an ideal day for Lewis Hamilton.

The Briton told Sky Sports News during the lunch break that he wasn't happy with the balance of his W08 throughout this morning. He was third fastest, with his best time a 1:20.456, 0.73 slower than Felipe Massa.

"We had some damage to the floor, but I didn't have any offs or anything like that, which is a good thing," he said. "Just a bit of an awkward balance today and I think the temperatures are a bit higher today, so it's harder on the tyres."

Rachel T: Can you post this Happy 14th Birthday message to my F1 mad son, Harry? (Just seeing if he is checking testing updates at school!!)

Happy Birthday, Harry! 

Now get back to your arithmetic!

Sebastian Vettel improves but still can't quite break the 1:20 barrier. His latest effort is three tenths off doing just that.

Vettel has also just completed his 100th lap of the day. He was the only driver to pass that mark twice last week. Smashing it.

Ian McCormack: Teams always hide their ultimate pace in testing - let's hope McLaren are the pit lanes hiding champions!  

Ben E Goat: Are McLaren trying to give mechanics as much engine change practice as possible so once the season starts they can do it quicker.

Daniel Ricciardo has been able to take his time over his lunch, with Red Bull doing a couple of set-up tweaks to his car. He's got the nod to head back out now. Sebastian Vettel is also on the track.

Nico Hulkenberg gets his running under way with a 1:26.076, putting him 13th on the timesheet. He finds a bit more a couple of laps later, doing 1:25.081 to move up one place to 12th.

There's movement in the pits! 

One of the two teams that needed to change engines in the morning is sending their driver back out. So is it McLaren or Renault?

It's the latter, Nico Hulkenberg makes his first appearance of the week, having taken over from Jolyon Palmer.

Lewis Hamilton has taken advantage of the time off the track to take Roscoe for a wander around the paddock. A fascinating update I'm sure you will agree. 

Image source, .

F1 journalist Dan Knutson in Barcelona: Some of the drivers have more to do at lunch than have lunch. Daniel Ricciardo did a meet and greet with Red Bull guests. Carlos Sainz posed for this photo shoot.

Joanna Harran: I keep on tuning into testing now and again at work hoping miraculous recovery from McLaren. So far, not so good. Fingers crossed.  

Matt RSJ: Hopes: McLaren get a podium and give us something to cheer about. Fear: McLaren don't get a podium and it be the same old rubbish.  

Any news on McLaren? Nothing I'm afraid since the confirmation of that engine change in Stoffel Vandoorne's car just before lunch.

There's no sign of the Belgian or Nico Hulkenberg. He is due to take the Renault out at some point this afternoon but problems in the morning meant they too had to change the engine.

Valtteri Bottas set the fastest time in testing so far this year last week but it's a steady start to the day for the Finn as a 1:24.675 puts him 10th, almost five seconds off the pace.

Ollie Maclean: If Williams really are as fast as they are in testing this season I'd love to see Massa win the title   

A few more engines fire up as Valtteri Bottas heads out for the first time this afternoon, softs on the Mercedes.

After a busy morning, Felipe Massa also gets back on it.

Puddy: Poor Alonso. McLaren has denied the F1-fan and spectator from enjoying Alonso's fantastic expertise as a F1 driver  

Greg Kingston: Have @McLarenF1, external ever come last in the F1 constructor's championship? Really fear that 2017 will be the year it happens  

Sebastian Vettel improves on his best time from the morning as a 1:20.387 sends him up to third on the timesheet. 

Marcus Ericsson has been out for an installation lap as the rest of the drivers slowly start to get involved in the action.

Action! Esteban Ocon is back out and also has Sebastian Vettel for company.

Ocon has supersofts on while Vettel kicks off the afternoon on softs.

Marcus Ericsson takes over from Pascal Wehrlein this afternoon but, 30 minutes in, he is yet to warm the Sauber seat. In fact, it's all quiet on the track because Esteban Ocon has gone back in.

A very uneventful start to the afternoon.

Lord Andrew Dennett: As a lifelong @McLarenF1, external fan this is getting beyond a joke!! Would be better of driving Fred Flintstones car at this rate!!  

Richard Elms: Surely it is better for McLaren to have the problems now and not during the races? Still looks worrying though ...