What we learned from the final day of F1 Bahrain pre-season testing

That was more like it. The first squeeze of suncream was required in order to spend any time in the Bahrain paddock or around the Sakhir track, as on Friday the sun finally broke through the clouds that had lingered all week.

This had implications for the 10 Formula 1 teams – as, even though the mercury never topped 19C, this was the same as the ambient race temperature here last year.

That rise cemented Carlos Sainz as the ‘winner’ of 2025 pre-season testing – if only in the misleading headline time stakes. His 1m29.348s from day two would end up 0.197 seconds quicker than George Russell managed in pipping Max Verstappen to top the test’s final day.

This came down to how the raised temperature impacted the tyre challenge here. The rough surface means, even when conditions are nowhere near as boiling as they can be, the drivers are struggling to keep the rear tyres alive. In pre-season, it’s also tricky to get the front axle balanced too.

Sainz sardonically quipping that his odd Turn 1 spin at the start of a performance run on the C4 rubber late on Thursday was “beautiful” gave away much of what the drivers think about the reworked compounds Pirelli has produced this year.

But Pirelli motorsport boss Mario Isola reckoned the C4 could be activated into working range better in Friday’s added heat. Williams was still the only team that ended up around the benchmark times on Friday to run with it – the C3 remaining the preferred option for most. It was the compound that typically forms the medium for many F1 races that Russell used to go fastest on the day.

Sainz leaves Bahrain with the fastest lap time in testing, but it will mean little for the season ahead

Photo by: Williams F1

The softer tyres are so useless on the outlier Bahrain surface – given how fast the rears wear out even over one lap – only Ferrari and Williams had bothered bringing any.

And they never got a look in, so F1 will have to wait – surely, with bated breath – for the first use of the new C6s that are set to appear for the first time at Imola and the comparatively smooth track surface there. It is not just a ‘Monaco special’ tyre.

Russell’s final time gave Mercedes a positive ending to testing, which could not be said of its rivals seemingly sitting in McLaren’s wake in the overall performance pecking order as 2025 commences: Red Bull and Ferrari.

Red Bull fears its RB21 isn’t responding well to the set-up tweak efforts – suggesting the team is having a hard time achieving its aim of widening its performance window

Red Bull would’ve at least had a headline to wave had Verstappen’s 1m29.566s held on as the final day’s best, but Russell deprived the world champion of top spot when he blasted around with fresh C3s with just seven minutes of pre-season remaining. Things were worse for Red Bull in both how the RB21 appeared for Verstappen and when it comes to what insiders are saying about the team's running in 2025 so far.

Verstappen spent all of the final day in the RB21 – testing its new nose with a series of install and correlation runs in the bright morning running. But, when he came to build up to a performance run – initially using the C2 tyres that are harder and therefore slower for 2025 – his balance was all over the place.

The RB21 wouldn’t turn in through Bahrain’s tighter sections, then was oversteering in its few high-speed parts. It came together enough for Verstappen to forge temporarily to the top of the times, but he too was a Turn 1 spinner late on.

Both Red Bull drivers endured spins during testing

Photo by: Sam Bagnall / Motorsport Images

Red Bull fears its RB21 isn’t responding well to the set-up tweak efforts – suggesting the team is having a hard time achieving its aim of widening its performance window, even if that means the car’s pace is lower overall.

The team did, at least, get through all the set-ups it wanted to try on Friday. And the wind was blustering stronger than ever this week which, as the 2024 Bahrain race showed, can have a transformative effect on the Red Bull package (for good or ill).

Things looked worse, however, for Ferrari. The Scuderia had lined up Lewis Hamilton to drive in what is typically the most important half day of Bahrain testing, but he had to abort his first race simulation of the week after Ferrari spotted a problem in its telemetry data. It is understood this was related to the gearbox hydraulics.

Hamilton ended up with just 47 laps for his half day (Russell, with the same potential seat time, did 91) and his race sim lasted just 12 tours before he pitted. It also featured Hamilton going off the road several times – mainly at the tricky double-left of Turns 9-10. He did try again for five more further higher-fuel laps, before his running was prematurely over.

His pace was also poor, coming in over 0.7s down in ‘first stint’ comparison on the full race sim completed by McLaren’s Oscar Piastri. The Ferrari just seemed to be severely degrading its C3 tyres.

That Piastri run consisted of 17 laps on the C3s, then 21 with the C2s and seven with the C1s for a 45-tour race sim total. His averages for these came in at 1m36.247s, 1m35.169s and 1m33.753s respectively – which was around 0.5-0.8s slower on each tyre compared to what Lando Norris had clocked on that eye-catching race sim in the less tyre-torturing Thursday running.

Russell, by comparison, was 0.542s slower on C3s, but improved to be just 0.059s off on the C2s and 0.123s down with the C3s. His stint lengths were all longer than Piastri did, too – at 18, 23 and 13 for a 54-tour total that better mirrors the real race distance here.

Hamilton had to abort his race simulation due to a problem Ferrari spotted in its telemetry data

Photo by: Sam Bagnall / Motorsport Images

Extrapolating the few lap times Hamilton was able to log during his aborted race stint through the three compounds puts him around 0.43s slower than Piastri managed overall in terms of total ‘race’ time.

Piastri might’ve been driving what most of the paddock considers to be the pick of the bunch, but he still lamented balance inconsistencies in the lunchbreak press conference.

But that’s F1 drivers, never truly happy. Even when they are, there’s danger lurking around the corner that their place will be usurped, as Red Bull found out last year.

Now, F1 just has two weeks to wait to discover if McLaren really is the favourite for the 2025 world titles…

With pre-season testing complete, F1 heads to Australia for the opener

Photo by: Zak Mauger / Motorsport Images