Decoding the teams' run plans in Bahrain pre-season testing

There's nothing quite like Formula 1's pre-season testing sessions to dust the winter cobwebs away. Endless viewing of watching the cars pound around a circuit, clocking in the laps for hours at a time, is box-office viewing - no wonder the fans love to watch it.

Facetiousness aside, testing isn't a particularly enthralling watch beyond the first hour - and it's not supposed to be. Suggestions from people within the F1 paddock that it should be subject to the same spice-up machine as race weekends seems to be counterintuitive to the point that it's genuinely all about just running continuously on track. Perhaps it's the anticipation of the unknown that lends curiosity; perhaps it's just seeing cars on track again...

Testing should be taken for what it is; that's not to say that it can't be enjoyed, but it should also be left alone for the teams to debug their cars and work out what makes them tick. Since there's only three days (plus change, with filming days and shakedown sessions) allowed, the usual checklist of test items must be ticked off in rapid fashion to ensure the cars are ship-shape for Melbourne's season opener.

Naturally, we're not privy to the overall run plans of each team, but we have an inkling of the tests that each one needs to carry out. Much of this is correlation work, with the aim of running the car in the same conditions seen in wind tunnel testing to see if the same results are applicable to the real thing. Expect to see aero rakes aplenty, especially on the opening day - these will host a series of Kiel probes or Pitot tubes, which measure the stagnation pressure of the airflow behind a certain aero device and can be used to produce a map of the pressure distribution around the car.

You can take that map and compare it directly to a "pressure slice" that you can record in CFD, where you pick a plane in much the same way and record the pressure at that point, or to a similar aero rake test recorded in the wind tunnel. If the overlay looks the same, then that shows the teams their simulations are correct - if not, then the aerodynamicists are likely to be thrown into a tizzy trying to work out why that is.

This will usually follow the installation laps, which are effectively systems checks for the car. If it leaves the garage, then that's a good start - it means the car is capable of achieving the concept of movement, undoubtedly an important milestone. On a more serious note, checking that the sensors are all providing read-outs and checking that the powertrain and brakes are all operating correctly will ensure that the team isn't about to get bogged down in the garage fiddling with parts when it could be data gathering. It sounds simple, but there are myriad examples of cars struggling to pass that first hurdle on the opening day of testing.

Aero rakes and system checks take the focus on the opening day of pre-season testing

Photo by: Sam Bloxham / Motorsport Images

In addition to the aero rake testing, there might be the occasional driver cruising down the start-finish straight at a constant speed. It might look like a car is about to peel off, but that's not usually the case - again, this is to verify that the pressure field matches the simulations at a given wind speed, and ensure that the aero is working correctly in relatively steady conditions.

All teams will be afforded the full gamut of Pirelli tyre compounds, assuming the new C6 tyre (developed for street circuits) will be in service. It would be surprising to see anyone explore the softer compounds on the opening days, as they're usually saved for the end-of-test flourish with performance runs. At Bahrain, wasting a set of C4s or C5s before nightfall will likely offer very little in return, although this year's expected cooler conditions might give teams reason not to adhere to that usual phenomenon.

Once the test has progressed from installation laps and aero rake tests, the schedule will move into the longer runs and what engineers term as "trying to break the car". The latter point is less in vogue these days, as the powertrains are time-tested and reliable, but it still behooves the trackside engineers to push the cars through long stints in an effort to provoke issues so that they can be fixed - or at least mitigated - for the opening rounds. In the case of McLaren in 2022, Bahrain testing exposed a brake duct issue that couldn't be properly fixed in time for the first race, but it at least gave the team an early project to focus on; in that instance, a manufacturing flaw was exposed.

Work on set-ups and determining how the car is best placed to use the tyres will form the meat and drink of the test, as this will hold the most importance when it comes to developments and preparation for the opening round

That said, the scant three days at the same circuit might not necessarily be enough to expose everything; that same issue barely reared its head in the preceding Barcelona test that year, particularly as everyone was preoccupied attempting to understand the new ground-effect aerodynamics and how to damp out the porpoising issues that had become evident during that opening week.

Thus, the teams will be focused on simulating every race eventuality in Bahrain; simulations on high fuel and low fuel to investigate how the car deals with cornering in extra load, assessing the aerodynamics in roll and yaw conditions to identify any instances where it might shed downforce, and maybe even a little bit of running in traffic to assess those downforce losses and how the car operates in turbulent conditions.

Tyre work will also be hugely important, and this is an area where Haas put a lot of its efforts in last year's edition of the Bahrain prologue - particularly as its 2023 car was hungry for Pirelli rubber. It paid off, as the VF-24 was one of the more delicate cars on the tyres through the year, so it wouldn't be altogether surprising to watch more teams eschew the performance runs to log more long-run mileage on the glut of compounds available.

Team have (almost) an endless supply of tyres in testing, meaning they can put in as much mileage as possible

Photo by: Mark Sutton / Motorsport Images

Don't expect too many long runs on the softest tyres, as Bahrain's quirks mean that it'll be difficult to assess how a car performs over a longer run on the C4s and C5s; the abrasive track surface does limit the opportunities to do so here. This will run in conjunction with set-up tinkering to determine which parameters are most likely to put the car in its most rewarding performance envelope, and how much latitude the car has with its operating window when the mechanics start adding in toe, camber, playing with spring stiffnesses, and the other variables available.

The work on set-ups and determining how the car is best placed to use the tyres will form the meat and drink of the test, or the plant-based alternatives thereof, as this will hold the most importance when it comes to later developments and preparation for the opening round.

At the end, we'll get the fun bit: performance runs. There's still a lot to be learned here, as it's a chance to put the understanding from the set-up tinkering into practice and unleash the drivers on the softest compounds available. It still won't tell us, the viewers, too much; most will be operating with more than the usual load of fuel to give us our allotted mention of "sandbagging" - the term we wheel out when a team wants to mask its performance by running at high fuel for the whole test.

Still, that final flurry against the clock is always pretty exciting. And the story goes that, in 2019, Mercedes felt it was somewhat lost with its W10 chassis until the final day of testing; that the car was particularly kind on its tyres versus the Ferrari's ultimate raw speed (acquired, allegedly, by surreptitious means of bypassing the fuel flow sensor) ensured that the Silver Arrows bagged another brace of titles that year.

For us as journalists, and hopefully educators, it'll be hard to deduce everything - but we'll endeavour to do our best to read between the lines and try to assess how each car is looking through the fog of war. Our predictions will invariably be wrong by the time the dust has settled on 2025, but what's the harm in that?

Pre-season testing can be fun, even if the bluff and double-bluff antics can become somewhat frustrating. Hopefully, you're feeling well equipped to settle down in front of the TV, mug of coffee in hand, to ask yourself the bigger questions about F1 testing - "how do we fuel-correct for the Alpine's qualifying pace?", "how long until someone copies the Mercedes front wing", and finally "it's Friday already? I've only just started logging the lap times for Sauber's Thursday long runs on the C2!"

Or perhaps, like Autosport did one year, start pondering which driver's name is worth the biggest Scrabble score - not including double- or triple-score tiles on the board. Antonio Giovinazzi won the last time we did that, so we might need a hand with updating it...

Three days of pre-season testing will fly by and then it is on to the season opener in Australia

Photo by: Erik Junius