A Formula 1 test in January, in the middle of winter, behind closed doors and with no media or fans in sight? Even by F1's occasionally unique standards, it feels a little strange.
But as cars quietly roll out at Barcelona this week, the sport is taking its first meaningful steps into a radically different future.
The first test at the Circuit de Barcelona-Catalunya -- officially labelled a "shakedown" by F1 -- takes place from Monday, Jan. 26 to Friday, Jan. 30.
Ahead of the track action, ESPN brings you all you need to know.
An F1 test in January? What gives?
In short, it's because of a complete overhaul of the power unit, chassis and aerodynamic regulations for 2026. Such a big change, especially on the engine side, means teams need a couple of extra tests to get their heads around how to operate the new cars before the first race.
It was the same last time we had a major power unit shake-up in 2014. Those with long enough memories may recall that Red Bull, the team that eventually finished second in the constructors' championship that year, only completed 21 laps of Jerez over the first four-day test!
While we're not expecting things to be that bad for the top teams, we do have two brand new engine suppliers in Audi and Red Bull Powertrains and one brand new team in Cadillac, which will all welcome the extra track time ahead of the first race.
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Why is it behind closed doors?
F1 is calling the first test a "shakedown," which is motorsport jargon for a short private test in which a team runs basic checks on its car ahead of its first proper test.
Internally, however, most teams are referring to the upcoming week in Barcelona as "Test 01" and all 11 have the opportunity to test for three days over a five-day period (Jan. 26-30), making this the de facto first test of the season.
Putting it behind closed doors will help hide the blushes of any team really struggling, but F1 being F1, it won't take long for information of low lap counts or repeated trackside stoppages to leak out.
Sources have indicated to ESPN that the real reason for calling it a shakedown and lowering the level of fanfare is because F1 has a contractual obligation with Bahrain to host the first official test in February. The more hype there is around Spain, the more it steals the thunder from Bahrain when the first of two tests gets underway on the island Kingdom two weeks later.
One clear advantage of hosting the first test in Spain -- rather than Bahrain or anywhere further afield -- is that it's closer to teams' factories, allowing them to leave production deadlines to the last minute and making it easier to deliver quick fixes to the track if necessary.
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What exactly are the rule changes and what prompted them?
At the heart of the regulation changes is a desire to have a hybrid power unit that produces 50% of its power output from the battery and 50% from an internal combustion engine fueled by advanced sustainable fuels.
That 50/50 target helped entice Audi into F1 for the first time as well as tempting Honda back from the precipice of quitting the sport in 2021.
But such an ambitious goal also comes with a number of complications. To achieve such a lofty target, there will be an even bigger emphasis on efficiency than before, to the point that the FIA has had to rethink the aerodynamic regulations as well as the power unit rules.
Cars will now have active aerodynamics on the front and rear wings (think last year's DRS at both ends of the car) to shed energy-sapping drag on the straights when the wings are open and maintain downforce in the corners when the wings are closed.
The cars are also smaller (10cm narrower and with a wheelbase 20cm shorter) and lighter (by 30kg) to make them more efficient and nimbler in wheel-to-wheel battles. Great in theory, but the bigger battery packs and larger MGU-Ks of the hybrid systems mean the overall power unit weight has increased by 34kg, creating a considerable packaging challenge to hit the new minimum weight while also meeting more stringent crash tests.
The above only scratches the surface of much wider changes to the cars for 2026, but basically we're looking at smaller cars with three times as much electric power. The implication is a brand new formula that is expected to introduce a new way of going racing.
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Have all the teams revealed their new cars?
Not yet. Some teams have shown us the real deal (Ferrari at its Fiorano launch, Mercedes from its Silverstone shakedown), some have shown us renderings of their car (such as Haas), and some have simply shown us showcars with their new liveries over the top (Red Bull and Audi, for example).
We had very limited glimpses of the real Audi and Cadillac when those two teams completed private filming days a couple of weeks ago, and a handful of photos and videos emerged from the public when the new Racing Bulls completed two days of track running at Imola this week.
Just to add to the variations in ways teams approach this preseason, those that haven't launched their cars yet are planning to take part in the Barcelona test with interim liveries while those that have are expected to use their full race liveries.
What can teams realistically learn from the test?
The main target for every team will be reliable on-track running while gaining as much data as possible about the car and its new power unit. So much of the talk about these new regulations is going to be around energy management as teams work out the best way to deploy the increased electrical power across the lap and, more importantly, how to recover that energy under braking and in corners.
The expectation is that the new cars will require a different driving style, so giving the drivers time to adapt will be key. If everything goes well, teams might have time to explore the performance and set-up of their cars, but the vast majority of that work will play out at the following two tests in Bahrain.
What teams and drivers are taking part? Will we hear from them?
All 11 teams had the opportunity to attend, but we now know Williams will skip the test due to delays with its new car. The other 10 teams are expected to be present at the test, and all drivers will be keen to get as much track time as possible ahead of the first race.
There will likely be some different approaches to which of the five days teams hit the track, especially if some are up against tight deadlines or have faced setbacks in the build process. McLaren, for example, will skip the first day of the test and possibly the second day after leaving its production as late as possible over the winter.
For what it's worth, the current weather forecast suggests Tuesday (day two) will be wet, so teams will likely aim to hit the track when it's dry for the most useful running. F1's cameras will be on the ground to capture some of the action and record short interviews, with UK broadcaster Sky Sports planning to produce highlights packages at the end of each day.
What won't we know because the test is private?
At a normal test, journalists have full access to timing screens and relative freedom to roam the paddock to speak to drivers and team members. The competitive picture is slowly pieced together from lap times and driver comments, and if things go wrong for anyone there is nowhere to hide.
That kind of access and depth of data will not be available next week, meaning a foggier picture will likely emerge from the five days. But the presence of teams spying on each other, marshals working trackside, and fans with camera phones poking over fences means plenty of material is likely to leak out.
There is, however, a danger of fake news emerging from the test, making it more important than ever to check reliable outlets.
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Who is expected to start fastest? And should we read into it?
That's the million-dollar question. Mercedes has been tipped as the best-placed power unit manufacturer going into the season -- a story that has ramped up in recent weeks amid reports it has unlocked additional horsepower with a different interpretation of the rules around the engine's compression ratio.
But the truth is that no one knows for sure, and even if Mercedes is leading the way, the true gap might not be clear from the scraps of information that emerge from Barcelona next week.
It's always much easier to pick out the teams that are struggling in testing, and any fundamental issues for a particular outfit or engine manufacturer are likely to leak out.
There will also be different approaches to testing, with McLaren already saying that its car will be largely unchanged between the Barcelona test and the first race, while Ferrari is planning to start with a more basic specification for reliability before bringing significant upgrades ahead of the first race.
After this test, what's next?
The teams will return to their factories to crunch their data from the first test and prepare for two further three-day tests in Bahrain in February.
There are also launch events planned for Mercedes, Williams, Aston Martin, and McLaren, as they unveil their race liveries for the upcoming season. The first race of 2026 will then get underway in Australia on March 8.