February marks the time of the year when F1 fans start getting excited again.

With the first race of the season getting underway in Melbourne next month, the teams first head to Barcelona where they unveil their new bodywork and start to throw off the winter shackles.

Though we won't truly know where the manufacturers are until the chequered flag brings the opening race to a close in Albert Park, the teams around the paddock are still desperate to get off to a good start this week and get laps under their belts.

As it was last year, the main question heading into the season is whether anyone can dethrone the formidable partnership of Mercedes and Lewis Hamilton.

The Silver Arrows have taken over from Red Bull as the sport's dominant force in recent years, winning the last five Constructor's Championships, with Hamilton winning four Drivers' Championships during that period too.

Only his former teammate, Nico Rosberg, has been able to been the Brit in that time.

Ferrari, who have played second fiddle to Mercedes in recent campaigns and are without a title of their own since 2008, have made key changes to their team both on the grid and off it, with Charles Leclerc brought into partner Sebastian Vettel and Mattia Binotto replacing Maurizio Arrivabene as Team Principal.

The Prancing Horse did make a promising start to testing, with Vettel topping the timesheets on day one. Red Bull, McLaren and Williams all expect to have improved campaigns, but Mercedes boss Toto Wolff has issued a warning to the chasing pack regarding Hamilton, stating that his no.1 driver is in the best physical and mental state he has seen.

Hamilton hit the track in the reigning champions' new W10 car in Barcelona as the team racked up over 100 laps on the challenger's official debut.

And Team Principal Wolff has been impressed with the five-time champion's fitness and mindset since returning from the winter break.

"The weight regulations have been lifted and he came back stronger and musclier than before," said Wolff, according to Sky Sports.

"He's in a super mental state, the best I've seen so far. He looks physically and mentally in shape - half an hour before the session started he was all ready to go."

Wolff insists that this attitude has filtered down to the rest of the Mercedes garage, with the team hunting an unprecedented sixth consecutive world championship double.

"It is very motivating. It wasn't done before but there's a reason why it wasn't done before, it's very difficult," said Wolff.

"It feels like you have 30 seconds left in the Super Bowl and you need to catch the ball. It's not trivial to catch the ball in the last pass and drag it over into touchdown.

"So this is a little bit how it feels, but Ferrari is going to do everything to not let that happen and, equally, some of the other teams."

Having seen Ferrari take the headlines on day one of testing, Wolff said his team's rivals already looked "ultra strong" but insisted Mercedes were focusing on their own performance rather than looking elsewhere too much.

"You need to be disciplined. We are all keen and looking at lap times and obviously you want to be quick and on the top of the leaderboard at every single session, but it's not the purpose of the test.

"It's to go through all the parts, and look at what the data and sensors tell you.

"I've seen the time and the time was very quick, two seconds quicker than everybody else, and definitely the Ferrari has been going strong this morning."

Wolff added: "We don't know yet how the competitive order is going to be.

"We feel no sense of entitlement for being top of the pack and this morning shows you why."

An intriguing few weeks lie ahead, as the teams race against the clock to get their cars ready, but once again, it looks like Hamilton and Mercedes are the ones to beat.