Audi has finished the engine it will run in testing although the specification it intends to make its Formula 1 debut with will be a "distant" relative as it pushes deadlines back to maximise development.
Work on the first F1 engine designed and built by Audi, which will power its Sauber-run factory team from 2026, has been ongoing since spring 2022.
A complete powertrain - engine and gearbox - has been running across 22 Audi test benches since last year, with the final endurance runs completed this autumn.
The very first Audi F1 engines are now finished. Construction is complete, the first fire-up of an engine installed into a chassis is coming soon, and from December some engines will be shipped to Bahrain for the February pre-season tests.
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However, F1's major rules overhaul in 2026 prompted teams to arrange a collective, private test at the end of January in Spain, too.
While logistically easier than Bahrain, it presents an earlier-than-usual challenge in terms of chassis and engine integration for the car's first runs.
The inaugural testing specification is locked in with a priority on reliability, which Audi F1 head Mattia Binotto described as "the biggest challenge we have ahead of us".
Audi will then push as hard as possible in developing the engine it will race in Australia in March. There is a deadline of March 1 for Audi and the other manufacturers to present a dossier detailing information of the V6 engine, MGU-K and so on, to F1 to get the engine a homologation that will be valid until the end of 2030.
Asked by The Race about managing the deadlines to get the engines ready against pushing development as far as possible, Binotto said: "To be ready means to be ready at the end of January - it means by early January the car is already assembled, and you start doing some tests back at the factory.
"The car needs to be ready quite early and we will fire up, by the way, before the end of the year. In the next weeks.
"The version we fire up and the version we go to testing with, the initial one, will be distant to the final one.
"It will make more sense when you go to racing, in Melbourne, we would like to have the best car we could have developed.
"So certainly we try to push as far backwards as we can all the deadlines.
"That's why, on one side, there is a necessity to start running: to understand the product, to understand the interaction, the energy management, the power unit to the chassis.
"And for us, as well, being the very first time we hit the track with a brand new Audi power unit, to make sure that the team is properly working together.
"It will be a brand new team that never worked together, because we have different suppliers in the past.
"So there is so much to learn. There is a deep curve of learning at the start that again [means] moving certain deadlines."
Audi's Neuburg facility has developed the V6 engine, MGU-K and associated hybrid components, and the gearbox, while the gearbox housing and rear axle are produced at Sauber's Hinwil base in Switzerland.
Where Audi and Sauber have worked most closely together on the engine itself relates to engine integration to maximise thermal efficiency and energy management, the latter being particularly important as increased electrification of the F1 engines for 2026 places an added premium on energy harvesting and deployment capabilities.
Audi's Neuburg facility has been heavily invested in and expanded to accommodate the F1 project, while Binotto's role as Sauber company boss was expanded to include oversight of the entire Audi F1 project - tapping into his technical experience from his Ferrari career prior to becoming team principal there.
"He was able to do a very quick initial analysis in Hinwil," Audi chief Gernot Döllner said when asked by The Race about Binotto's impact over the past 12 months.
"From there on, he developed, together with the team, a clear plan for this year.
"We are quite happy how that plan became reality. It’s the same thing on the engine side in Neuberg.
"With his background and experience, it was clear to bring him close to the Neuberg team.
"We have clear performance measurements on both sides and follow a clear development strategy. We are absolutely happy regarding that."
Once the engine is homologated, the general rule is that upgrades will only be allowed in the winter and finalised before the start of the subsequent season. Minimal incidental changes for packaging reasons may be carried out in-season with FIA approval, so may modifications to components for "the sole purposes of reliability, safety, cost saving, or supply issues".
However, if Audi's engine has a significant enough disadvantage, it will be given chances to catch up.
A performance index will be created for each manufacturer's V6 engine and 'additional development and upgrade opportunities' will be afforded to manufacturers through the year.
There will be three periods from races 1-6, 7-12 and 13-18 and at the end of these periods a manufacturer eligible for extra development can implement further upgrades, extend the usage of their test benches, and adjust their cost cap spending to accommodate it.
This will be based on how far off the performance index a manufacturer is - more than 2% but less than 4% below the best engine allows for one additional upgrade; more than 4% and a manufacturer gets two upgrades.
It is possible that Audi will need to utilise this system, though more likely in the first couple of years, and use its first seasons as a works team to improve in competitiveness before being ready to maximise a likely new set of car and engine rules some time around the end of the decade.
Sauber is currently in a fight for a respectable sixth in the championship but Audi has targeted being able to fight for championships in 2030.
"We did some benchmarking," said Döllner. "We had some experience from other race series.
"We found that quite ambitious but realistic. So that's where it came from.
"We have a three-phase model. We start as challengers, then we want to become competitors, and then in the third phase from 2030 on race for the victory."
