At the moment, Lewis Hamilton, the pacesetter so far this morning.

Last year's first test was around the Jerez circuit, which is 4.428 km in length compared to 4.655 km at the Circuit de Catalunya.

Sebastian Vettel set the pace on his Ferrari debut in the first test last year, but that was at Jerez.

Here's the results from the first day of the first test last year:

1) Sebastian Vettel (Ferrari) 1:22.620 60 laps

2) Marcus Ericsson (Sauber) 1:22.777 73 laps

3) Nico Rosberg (Mercedes) 1:23.106 157 laps

4) Daniel Ricciardo (Red Bull) 1:23.338 35 laps

5) Valtteri Bottas (Williams) 1:23.906 73 laps

6) Carlos Sainz Jr (Toro Rosso) 1:25.327 46 laps

7) Fernando Alonso (McLaren) 1:40.738 6 laps

Andrew Benson
Chief F1 writer

“What will be revealed of McLaren-Honda in the next four days? After a torrid 2015 spent at the back, big improvements are expected - and have been promised - from the team, especially concerning the Honda engine. There was a report in Spain last month that claimed Honda had found 223bhp for this season. That would put them not far from the competitive ballpark. 

"However, the word on the street in F1 about the progress Honda has made over the winter is not especially promising, and there was a distinct lack of predictions about their expected competitiveness in their launch material on Sunday. Last year in testing, reliability hindered attempts to make any real progress. Can they at least have a decent run over the next four days? 

"Jenson Button is in the car today, with Fernando Alonso driving on Tuesday.”

He has been out, but it was a blink and you'll miss it appearance. Jenson Button popped on to the circuit for an installation lap early doors, but has not been out since.

Fair point here. What are the worst cliches in F1? Let me know via #bbcf1, external

Not so much a cliche, but in my opinion a new driver is never truly an F1 driver until they have used "for sure" in an interview.

One hour and 43 minutes into the first day of the first test, and the Force India breaks cover just as Lewis Hamilton puts his foot down on the pedal to clock 1:27.735 - the fastest time so far.

Still pretty quiet on the circuit. The Manor appearance, though beautiful, was brief and they are back in the pits leaving just Jolyon Palmer, who plants the Renault at the top of the timesheet with a 1:33.389, set on medium tyres.

He heads in and as he does so fellow Briton Lewis Hamilton goes back out.

F1 journalist Dan Knutson: "The rules governing exhausts have been changed for this year in an attempt to make the engines louder, after criticism in certain quarters of the noise produced by the turbo hybrid engines introduced to F1 in 2014. 

"The cars have not been doing many flying laps, so its a bit early to say for sure. But I did a straw poll around the media centre, and the general consensus is that they are not. One journalist said he had not even noticed any change until I asked him. Another said there was no difference from last year. Several journalists said that the engines were “a bit” louder, so perhaps the 12% increase in noise that Williams technical chief Pat Symonds predicted is about right. 

"Former F1 driver Marc Surer said the engine note is a bit “sharper” this year but not that much louder. We will have to see what the noise is like when there are more cars on the track, and when the drivers really start going full speed."

Well hello there...

Right then, the Manor is rolling out on to the circuit for the first time. Shall we take a look at its look?

Image source, Williams

Williams' W38 sports the same red, white and blue stripes as the past two editions. Nothing radical going on here, but why bother shaking things up? It is a beautiful looking car.

Image source, Getty Images

Plenty of tinkering going on and feedback being given in the teams' garages, with just Jolyon Palmer out on track at the moment.

Four drivers have completed timed laps with Williams' Valtteri Bottas leading the way with 1:35.719.

The other three are Daniel Ricciardo (1:37.610), Lewis Hamilton (1:41.154) and Carlos Sainz (1:44.385). Not that the times mean much in testing of course.

Andrew Benson
Chief F1 writer

“Force India are another team to unveil their new car on Monday - in a now-standard, here-it-is-now-let-us-get-on-with-it style. It looks - how shall I put this? - really quite similar to the old one, which was a solid upper midfield contender last year. 

"Technical director Andrew Green explains: ‘You can say the B-spec car from last year formed a basis on which to build our 2016 one. We were in a situation in which the performance on track was very good, and in which the data we were getting correlated well to what we were expecting, so we knew we could continue to develop on a solid platform. With the regulations likely to change for 2017, it didn’t really seem like an efficient use of our resources to start from scratch on a project that would have such a limited lifetime.’”

The hairs on the back of my neck just stood up listening to this (click on the link above). Loud and proud.

Force India revealed the VJM09 earlier this morning, but hasn't been out on the circuit yet this morning. The team are just putting the finishing touches to it apparently, and it should be making an appearance any time soon.