DOMINANT DISPLAY: Mercedes driver Nico Rosberg mounts the kerb on the third test day of the Formula 1 season. The Mercedes team showed no signs of letting up, with 675 laps of testing in four days. Image: AFP / Josep Lago
Barcelona, Spain - The first Grand Prix of the 2016 Formula 1 season in Australia is less than a month away on March 20.
After the first four days of pre-season testing in Barcelona, we look at 5 things that can be learned from the early pre-season tests.
1 Mercedes still miles ahead
Mercedes didn't post any flashy times and refused to put on any of the faster soft tyres but pounding out 675 laps in four days was a statement of intent from the reigning double world champions.
Reigning champion Lewis Hamilton claimed to have "never had a week like this" in his preparation for a third consecutive title, whilst McLaren's Fernando Alonso ominously declared "Mercedes' dominance didn't finish" and warned that the team may be stronger than ever.
Having won 32 of 38 Grand Prixs since 2014, it is hard to imagine anyone threatening another title battle between Hamilton and Rosberg.
2 Ferrari speed encouraging
Ferrari posted the fastest time on three of the four days to boost hopes that, having been the only man outside Hamilton and Rosberg to win a Grand Prix last season, four-time world champion Sebastian Vettel could post a stronger challenge this season.
Vettel was happy with what he described as a "step up" from the SF16-H, but there is also a cause for caution in Ferrari's bid for a first world title since 2008.
At the first test in Jerez last year Vettel and Raikkonen also topped the time sheets in three of the first four days but were eventually left well behind once Mercedes began to flex their muscles.
3 Much to do for McLaren-Honda
Hopes for a fresh start for the beleaguered McLaren-Honda partnership were quashed by a final day-and-a-half to forget in Barcelona as the MP4-31 barely made it out the garage due to hydraulic and cooling problems.
Reliability issues and a lack of engine power saw the once great McLaren finish second last in the constructors' championship last season despite having two world champion drivers in Alonso and Jenson Button.
Yasuhisa Arai is to be replaced by Yusuke Hasegawa as chief motorsport officer of the giant Japanese car manufacturer's F1 activities, but there is little evidence they have the tools to propel themselves back to the front of the grid.
4 Force India to be third force?
Arguably the most eye-catching time of the week was Nico Hulkenberg's in the Force India that topped the timings on Wednesday.
Most notably, the second best time of the week from Hulkenberg came on supersoft tyres, whilst the other three of the top four times came on the faster ultrasoft.
Sergio Perez also had the fastest time of anyone on soft tyres.
It may be unrealistic to imagine Force India upsetting Mercedes and Ferrari's applecart, but they certainly seem well set to challenge the likes of Williams and Red Bull to be the third force.
5 F1 is an unhappy camp
The FIA's decision to revolutionise qualifying with a knockout system was met with a mixed reaction.
The intent to try and inject excitement back into the sport is welcomed, but there is doubt as to whether this was the best way to go about it.
Hamilton certainly didn't believe it would challenge his superiority when he claimed it is likely to make little difference.
Meanwhile, at the same time a decision on regulations for the 2017 season has been pushed back to April 30, a delay which Williams boss Pat Symonds thinks will harm smaller teams and create exactly the inequality that it is hoped new rules can eradicate.