Helmut Marko has explained Red Bull RB21 issues after a mixed bag of results during Day 2 of the 2025 F1 Bahrain pre-season testing.
While the new challenger has shown flashes of promise which Verstappen described as ‘only good surprises’ after a solid run, a technical issue involving a cooler leak disrupted their morning session, cutting into valuable track time for Liam Lawson.
Despite the Red Bull RB21 issue the team remains optimistic about the car’s potential with senior advisor Helmut Marko offering insights into both the challenges and strengths of their new machine.
The cooler leak on the RB21 was a significant hindrance to Lawson’s running during the morning session. The New Zealander managed only 28 laps before the energy drinks outfit had to halt operations to address the issue.
According to Marko, the malfunction cost the team approximately 40 minutes of track time a critical loss during such a condensed testing window. The team eventually resolved the problem, allowing Liam Lawson to complete 91 laps by the end of Day 2 at the 2025 F1 Bahrain pre-season testing.
However, the Red Bull RB21 issue coupled with disruption of track action due to intermittent rain in Bahrain meant the Milton Keynes based team could not fully execute their planned testing program.
“We had a handicap today due to the rain and we were not able to complete our entire test programme,” Marko told motorsport.com. “Other than that, though, it was a normal day of testing and we ran different parts of the programme.
“There was a leak in one of the coolers. That cost Liam at least 40 minutes of driving time.“
Marko downplayed the impact of these setbacks, describing them as typical challenges during pre-season testing. He emphasized that despite the interruptions, Red Bull was able to gather valuable data and remain “in line” with their expectations for the RB21.
“It would of course have been better if we didn’t have those problems, but we still did what we could,“ he added. “And this is still in line.”
The Red Bull RB21 issues come just a day after the car received glowing reviews with both Verstappen and Lawson praising its predictability and responsiveness after a promising run in Day 1 of 2025 F1 Bahrain pre-season testing.
However, Marko reiterated that these positive impressions remained valid despite the challenges encountered on Day 2.
“The long runs were really competitive; it was the fastest,” he said. “The car is more predictable and reacts to the changes in the normal way.
“So, all the problems we had last year, I believe they are much better, or maybe they are also sorted.
“Max says the car is more complex and is more put together, and whatever they do on changes, the car is reacting in the right way.
“On his fastest lap, he had a little problem, so it could have been [quicker]. But anyway, we say that long runs were really impressive and our tyre wear was very good. The car has the wider range and is more predictable for the drivers.”
Helmut Marko also took note that Verstappen’s new team-mate Liam Lawson has made a bright start to life at Red Bull’s A-team, though he is still exploring how to get the most out of the medium tyres.
“He did a good job,” Marko added. “He just couldn’t gain when he changed from hard to medium.
“We also changed something on the car, which didn’t work, and he said it was the wrong decision. So, everybody was gaining three to five tenths, and he just gained one tenth.”
The team will be looking to solve underlying Red Bull RB21 issues before Day 3 as Verstappen is set to take over driving duties.
