Horner's inside story of how Red Bull built its own F1 engine

Red Bull's recent Formula 1 form has demonstrated the clear progression that the team has made with its 2026 car, but there's one aspect of it that has largely remained unchanged - thanks to the current regulations.

Its powertrain, the Red Bull-Ford DM01, was pegged by the FIA as having F1's most powerful engine, and thus has not been eligible for any changes under its additional development and upgrade opportunities (ADUO) despite its assertion that Mercedes has the best all-round package. But, as now demonstrated by Max Verstappen at both the Bahrain Grand Prix in Malaysia and the Singapore Grand Prix, it is now a race-winning powertrain. At times, it has been very easy to forget that this is Red Bull Powertrains' first season as a manufacturer, but it deserves considerable credit for its successes this season. 

Red Bull's journey as a powertrain supplier concluded 20 years of hopping around the other manufacturers on the grid, taking its destiny into its own hands. After a year with Cosworth and a year with Ferrari, Red Bull made the decision to switch to Renault for 2007, passing its Ferrari deal over to Toro Rosso in the meantime. While the Red Bull-Renault relationship started well, particularly as the two united to lobby the FIA for changes to the engine-freeze regulations in force at the time to allow the French marque to find more power, it began to sour at the dawn of the turbo-hybrid era. Renault's first effort for the 2014 engine regulations was down on power and unreliable, relating to a series of software issues during testing where the MGU-K and the internal combustion engine were simply not working in unison.

While the reliability issues were mitigated, Renault struggled for power delivery; Ferrari had been down on power through 2014, but soon overtook it. Red Bull tried to negotiate a deal with Mercedes when it became clear the Renault relationship was not going well, and got as far as a handshake with Niki Lauda before CEO Toto Wolff vetoed the deal. Instead, Red Bull was forced to extend with Renault for a few more years, rebadging its engines with "TAG Heuer" branding to create some degree of separation.

Then came the opportunity with Honda. Since aligning with Honda for 2015, McLaren had hoped to recapture the magic of their first relationship between 1988-1992, but the Japanese brand was struggling to meet McLaren's stringent packaging demands and also struggled vastly with reliability. A switch in engine concept for 2017 did not work out, and McLaren was looking for the exit; a lifeline emerged when it agreed to switch engine deals with Toro Rosso for 2018, giving the Italian team the Honda deal and for Red Bull to assess its progress. When Honda began to show increased competitiveness, having spent the year rifling through engine specifications (and subjecting drivers Pierre Gasly and Brendon Hartley to myriad grid penalties), Red Bull pulled the trigger and took Honda on for 2019. 

But the partnership ultimately didn't last despite its successes. With Honda, Red Bull won its first title since 2013 as Verstappen beat Lewis Hamilton to the 2021 drivers' title, but Honda had already elected to pull the plug by the end of the season. With no other real options, Red Bull issued the FIA with an ultimatum: freeze the current powertrain regulations and allow the team to retain Honda's powertrains (and effectively pay the company to maintain them until the end of 2025), or both teams will walk. The FIA agreed, and Honda ended up retaining some involvement in the engine project, but the seed of Red Bull going it alone had already been planted in Christian Horner's mind. 

When Horner sat down with Autosport to discuss his career and his new book Drive: A Memoir, he discussed how Red Bull's own engine project came to be - and how it developed up to its racing debut at this year's Australian Grand Prix.

Watch: Christian Horner on Toto, Abu Dhabi 2021 and Life After Red Bull | Full Interview

"Red Bull had always been a customer for all of its engines, whether it would be with Cosworth within the first year, Ferrari in the second year, Renault thereafter, and with Honda we were a customer team," he began. "When Honda announced their withdrawal from the sport just after or during COVID, it was a question of 'okay, what are we going to do?'

"To go back to Renault, we've been there and done that; Ferrari would have offered an engine, but Red Bull are quite a demanding customer, Mercedes obviously wouldn't supply an engine or they would have had too many teams, so it's a question of 'do we either accept mediocrity as a customer team, or do we take control of our own destiny?'

"And that went hand-in-hand with the requirement of new regulations and a budget cap, which were confirmed in February 2021. As soon as that was confirmed then we created two companies, so there was effectively the Red Bull Powertrains 'current' which was for the Honda-related activities, and then there was a Red Bull Powertrains 2026 which was for the new engine and new project. 

"We did a deal with Honda, because they were pulling out, for any of their staff in the UK which were all operational staff and a few battery-related people came across into the business. But we needed to start from scratch [for the 2026 project], it was a startup and the shareholders signed it off because of the budget cap. In 2021, if we weren't at a racetrack we still had COVID restrictions during that period. I was interviewing an awful lot of people here from Mercedes, trying to convince them to come across to this crazy new project, but using what we'd done on the chassis as a prerequisite to say, 'look we've done it on the chassis, I believe we can do it on the engine with the right people'.

"You've got several engine businesses in the UK; you've got the most prevalent being HPP [Mercedes High Performance Powertrains] and you've got Cosworth and you've got Ilmor, but there were no new engine businesses within the UK for the last 25 years. What you had at HPP was a fairly sort of stagnant organisation that people were almost waiting for dead men's shoes to be able to progress."

At the time, the number of employees moving from HPP to RBP was quite significant; by the middle of 2023, this was understood to be around 120 employees as Horner lured them to the new project. Mercedes, as was their wont, played the impact of this down - but its engine leader Hywel Thomas had admitted at the time that it did force HPP to rethink its recruitment processes, and to put more of a premium on graduates to fill the voids left by those moving from Brixworth to Milton Keynes.

As Horner said, there was a wealth of people at HPP looking to make the next step, but without the opportunity to do so, and also those working at Red Bull who wanted to move away from the chassis side of the business and try something new. Keeping the business in the UK allowed for a more seamless pipeline from Mercedes to Red Bull, even if talks were apparent in basing the Powertrains division in Austria.

Project leader Hodgkinson was one of those to make the switch from Brixworth to Milton Keynes

Photo by: Mark Thompson / Getty Images

Partnering with AVL was one such option. Based in Graz - conveniently enough, just over the road from one of Helmut Marko's hotels - the Austrian company has been a silent partner for many motorsport brands and houses state-of-the-art simulation equipment and testing rigs, and this was viewed as a way for Red Bull to build up its infrastructure without too much capital expenditure in assets already available. But Horner was keen for everything to be done in house - and eventually, the shareholders relented.

"By saying we're going to put this in the UK, it was a fundamental decision," he explained. "Again, there was a discussion of do we partner with AVL and do it in Austria, or base it at the circuit at the Red Bull Ring, or whatever. Having convinced the shareholders that we need to be in the UK, identifying that we had the space within the campus - we had a building that used to be a bubblewrap factory, that we managed to do a minor update to as far as the planners were concerned - and build a new factory within 55 weeks and start recruiting the right people. 

"That was a process where we were getting into a tug of love over talent, and I was aggressively recruiting out of Mercedes. Ben Hodgkinson was a was a key recruitment in the early days, Pip Clode on the turbo, coming across Phil Prew and so many talented people that we managed to attract out of HPP, and giving people the opportunity from within the business that perhaps wanted to make that step into other parts of the organisation.

"It gave an opportunity for talent to try something different. You had departments that were going to be affected by both, so for example electronics had to grow overnight to accommodate both chassis and engine and hadn't produced engine wiring looms before. It was a really dynamic period, we employed some great characters like Steve Brodie from Mercedes and they just came with such energy and passion for the project.

"It was a really exciting time; there was a lot of questions even internally because Honda had produced an engine that was giving us the ability to fight for world championships, toe-to-toe with Mercedes, and our biggest risk was going to be this new power unit. Indeed, sponsors were asking those questions, 'how much of a risk is this?' Drivers, there was concern with drivers about if this engine is going to be competitive. You had to take hearts and minds on that on that journey and say 'guys, Honda is not an option. This is it, we're in it together, we have to make it work. Their success is your success, their failure will be your failure, so help them.'"

Transplanting so many staff from Mercedes into a new entity had its issues. In developing the facilities, the engineers were given opportunities to effectively shape the factory into a similar layout to what they were used to, albeit with a few changes to ensure the workflow was slightly more efficient. For Horner, as he sought to get the lay of the land and integrate his new staff with 'The Red Bull Way', he soon found himself up against those for whom 'The Mercedes Way' had been ingrained. 

Red Bull secured a wealth staff from Mercedes' High Performance Powertrains - with the express purpose of beating their former employer

Photo by: Andy Hone/ LAT Images via Getty Images

Like Ross Brawn banning La Gazzetta dello Sport from being circulated in the Ferrari office on moving to Maranello, as he was concerned about the morale hit caused by the Italian media, Horner soon placed similar restrictions on the word of their former employer. "There was too much talk of 'well at Mercedes, we did this - at Mercedes, we did that'. In the end that got banned from meetings and saying that we're not going to mention Mercedes - it became Team B!"

By 2022, Red Bull had its first single-cylinder prototype on the dyno, allowing it to explore pressures, temperatures, combustion profiles, and the fluid dynamics research associated with the intake and exhaust phases, plus structural integrity. The Powertrains team was also able to move into the new facilities built in Milton Keynes, on location at the Red Bull Technology Campus to keep everything almost under one roof.

However, there were concerns about Red Bull doing everything alone; even with the removal of the MGU-H for 2026, the Powertrains team needed to cover design of the MGU-K, the turbocharger system, and the battery to feed the uprated motor producing 350kW at the rear axle. This is where Porsche entered the story.

Around the time of Red Bull's first prototype explorations, the Volkswagen Group (VAG) was looking very seriously at Formula 1. This was a tale as old as time, however; Porsche and Audi had been linked with F1 intermittently over the previous couple of decades, but these amounted to nothing - and those rumours seemed to evaporate when Volkswagen was caught in the Dieselgate emissions scandal of 2015, having been found to be cheating during emissions testing. Having been part of the F1 powertrain discussions for 2026, however, Volkswagen's sub-brands had found renewed interest in being part of F1. 

Red Bull and Porsche thus came into contact, and were in very serious negotiations about joining forces for 2026. For Porsche, it was a gateway to get into F1 without completely investing in all-new resources, while Red Bull would have the support of a performance-car brand and performance-car expertise. But the deal never came off; Porsche wanted an even split in the partnership, but Red Bull did not want to cede control of the project it had built from the ground up. By September, the talks over a deal were dead in the water.

"Within a year we had our first prototype engine up and running, but I think there was still some nerves within the group within Austria of 'could we produce a competitive engine?' and then Porsche suddenly came as a possibility," Horner recalled. "I think in Dietrich [Mateschitz]'s mind, by this stage he wasn't in great shape, but he saw the benefit of the Porsche brand, an amazing brand, and a 'Red Bull Porsche' was really premium.

Porsche almost joined fellow VAG brand Audi on the 2026 grid, but talks with Red Bull fell through

Photo by: Mark Sutton / Formula 1 via Getty Images

"They make engines, we don't, and so we explored that. I went to Weissach and saw some of their facilities and recognised that we were miles ahead in terms of what we were doing in preparation for Formula 1 than where they were. And it felt like there was going to be a lot of compromises bringing these two entities together, there'd be challenges in the direction in a 50-50 partnership and so that deal didn't go through in the end.

"But we needed a partner, because it was a big burden. I was very conscious of turning the Porsche deal down, because the whole engine cheque was sitting on Red Bull's hands. They were paying for Honda to stay in Formula 1, they were paying to build their own engine, and of course, they've also got two grand prix teams. Then, Ford Motor Company were looking at around F1 at the time."

The story goes that Red Bull was due to announce the partnership with Porsche at the Austrian Grand Prix of 2022, but the concerns over control proved too much of a stumbling block. Honda hadn't yet committed to its return for 2026, and wouldn't do so until it confirmed its tie-up with Aston Martin in May 2023, but had held talks with Red Bull about linking up as a partner to its powertrains project.

Then Ford entered the frame. In the Blue Oval's talks with Red Bull, it became apparent that the Detroit manufacturer was not nearly looking for as much in return as Porsche; it wanted a way into F1, but was willing to take a hands-off route. Red Bull wanted support on its own terms, and Ford was willing to supply that through its expertise with electric vehicles and the technology outside of the development of the internal combustion engine.

"I went to Detroit and had a meeting with Bill Ford and Jim Farley, and straight away you could see there was an enthusiasm for them to come, having been involved in the team in its previous iteration," explained Horner. "Bill Ford said to me 'you're the specialists, the learnings that we had from our last experiences, we don't want to over-involve ourselves in your business. How can we help you? How can we support you?' That partnership got going in time for the 2023 season."

With Ford on board, Red Bull had its desired support from a manufacturer. And, as 2026 dawned, Red Bull demonstrated the strengths of its powertrain; as soon as pre-season testing began, Mercedes had heaped praise on the Red Bull-Ford powertrain as the all-new F1 cars ran for the first time at Barcelona and Bahrain. Sure, some of this was politically charged and a way for Mercedes to play down its expectations, but some of it was also genuine praise. Few expected an all-new manufacturer entity to be so competitive from the get-go. 

Red Bull has now racked up two grand prix wins as a manufacturer team, a feat that automotive giants like Toyota and Peugeot were never able to achieve during their significantly longer spells in F1, and more than Porsche achieved during its own works project in the 1960s. Horner, of course, was not there to see it. 

Horner, here talking to Ford's Farley, found support from the Blue Oval

Photo by: Red Bull Content Pool

Having been dismissed from Red Bull mid-2025, bringing an end to his 20-year tenure in charge (and the political ructions that emerged in early 2024 when he was accused of misconduct by a female employee, of which he was later cleared by an internal investigation), Horner nonetheless takes pleasure from seeing the engine company he'd played a significant role in building up find such success. 

"It was arguably the biggest challenge I had in my time at Red Bull - because [initially] there was nothing," he remembered. "It was a complete startup and so therefore to see the milestones that that engine was achieving, we built our own manufacturing facility, manufacturing pistons and machining cylinders and the solid blocks and all this, it was amazing to see the commitment that went into that project.

"It was scary as hell because we had no experience of building engines but bringing in and backing the right talent, giving people the chance, and the satisfaction of seeing that engine win in its 16th race in its first year...I take great pride in that and tremendous pride in in the people and what they've done and achieved. 

"In many respects it's easy to underestimate the challenges of taking an engine from scratch, particularly within the most complex set of engine regulations in the history of the sport, and beating teams and manufacturers with so much more experience."