Jenson Button has finally posted a lap time in the McLaren Honda, but his 1:31.479 - some 6.5secs down on Hamilton - suggests the team is still finding its legs on this first morning.

McLaren chairman Ron Dennis has been pictured in the back of the team garage. There's a man with plenty to think about.

Force India have endured a troubled pre-season programme, skipping the first test in Jerez and then running a modified 2014 car in the second.

However, the team said this week that they would have their new challenger on track this Friday - and a tweet this morning has confirmed the new motor is boxed up and on its way from Silverstone to Spain.

"Our VJM08 is currently on its way to Barcelona; we'll be aiming for action on Friday afternoon and on the two full final days," the team said.

The team added that after the car is "completed on Friday morning", Nico Hulkenberg will be first behind the wheel. The German and Sergio Perez will share driving duties across the three days.

Image source, Force India

Andrew Benson
Chief F1 writer

"All teams will have upgrades at this test, with a view to preparations for the first race. And Toro Rosso's is the first to break cover.

"The team have a new front-nose design, replacing the smooth, rounded nose design of before with a Williams/Red Bull-Style stump. The aim is to improve airflow under the car - and thereby increase downforce - while satisfying the new safety regulations."

Image source, Getty Images

As you're reading this blog there's every chance you dream - or once dreamt - of being an F1 driver.

So it's good to know Lotus' Romain Grosjean is fully appreciative of where he is today.

"Wishing you all a very good day!" he wrote on Twitter., external "I'm where I love being, behind the wheel..."

Image source, Lotus F1

Meanwhile, that ominous-looking Mercedes is still pounding away. Hamilton improves to 1:24.881 on the medium tyre. That's around five-tenths off the pace team-mate Nico Rosberg managed on the same tyre on the final day of the second test at the same circuit.

The Sauber team have posted this rather lovely picture on Twitter, external of Marcus Ericsson sitting patiently at the end of the Barcelona pit lane waiting to light up his tyres with a practice start.

As you can see, it's a perfect day for a good hoon around the Circuit de Catalunya.

Image source, Sauber

After a trouble pre-season testing programme so far and driver Fernando Alonso sidelined, there's plenty of interest in the progress of the new McLaren Honda car.

Jenson Button, complete with new Niki Lauda-esque helmet, is the man behind the wheel today and it's been a low-key start so far - just two installation laps from the Briton and no time on the charts as yet.

Image source, Getty Images

With Hamilton top of the pile now seems as good as time as any to bring you a line from Red Bull boss Christian Horner, who believes Mercedes are still the team to beat in Formula 1, describing them as "the benchmark".

Horner was speaking on a special F1 edition of A Question of Sport broadcast last night.

If you missed last night's show, it will be broadcast again on Friday, at 19:30 GMT on BBC One.

Lewis Hamilton has set the early pace inside the first hour, the Mercedes driver quickest in a time of 1:26.437 on the medium tyre, around four-tenths up on Williams' Felipe Massa, who is on the hard.

Toro Rosso tweet:, external "Carlos is back in the garage.. Spot the changes on our car. We're running a new package #GOTOROROSSO"

Image source, Toro Rosso

Kimi Raikkonen's settled in to a few decent laps so far.

He opens up with a 1:32.451 and immediately wipes it off with a 1:30.7, a 1:30.692, a 1:30.271 and a 1:30.526.

Image source, Getty Images

Kvyat's RB11 is pushed to the garage after a nightmare start for the Russian. Green flags are out and Lewis Hamilton joins Raikkonen out on the track.

Not a great start to the day for Kvyat. He sets off for an installation lap and only gets as far as the end of the pit lane before grinding to a halt.

Out comes the red flag.

Image source, Getty Images

So, as well as Kimi Raikkonen, who as Lee McKenzie said has been first out on the track this morning, we're expecting to see seven other drivers go through their paces today.

Fresh from his red carpet appearance at last night's Brit Awards, world champion Lewis Hamilton will be heading out in his Mercedes, Jenson Button will put the McLaren through its paces, Marcus Ericsson will test out the Sauber, Romain Grosjean his Lotus, Daniil Kvyat in the Red Bull, Felipe Massa for Williams and Carlos Sainz in the Toro Rosso are all set to head out today.

Andrew Benson
Chief F1 writer

Image source, Reuters

"There is much to dwell upon as the final pre-season test of 2015 gets under way.

"Two weeks before the F1 circus sets up camp in Melbourne's Albert Park, teams will be introducing first-race upgrades to their cars these four days in Barcelona, and trying to tick all the boxes in terms of preparation.

"There will even be a new car to look at in the shape of the 2015 Force India.

"But before the cars are shipped off to Australia one question hangs above all others - will Fernando Alonso, arguably the sport's greatest participant, even be there?"

Lee McKenzie
BBC F1 pit-lane reporter

On Twitter:, external It's cold in Barcelona at the final #f1 preseason test and it's Raikkonen who is the first car out on track

After the briefest of breaks, the teams and drivers are back in Barcelona.

It's the final four days of pre-season testing before the big off in Melbourne on 15 March.

With preparations for the season opener at Albert Park ramping up by the day, and crucial mileage still to be accumulated, we'll bring you all the latest twists and turns from the track.