Red Bull team principal Christian Horner believes his team are currently at a "70-year disadvantage" compared to title rivals Ferrari ahead of the introduction of new engine regulations in 2026.
The reigning constructors' champions are in the process of building their own in-house power units through their Red Bull Powertrains division following the departure of Honda in 2021.
The upcoming rule changes will result in the Motor Generator Unit - Heat (MGU-H) becoming redundant, as F1 strives to achieve net zero CO2 emissions by 2030.
Speaking to media after last weekend's Chinese Grand Prix, Horner admitted that his team are some way behind Ferrari in terms of their understanding of manufacturing power units.
"We're on a steep learning curve, where we've got about 70 years of disadvantage to Ferrari," Horner conceded.
"We've got a great group of people, we're applying the same philosophy as we have on the chassis to the engine. It is a different challenge.
"There are no guarantees, and there is no knowledge of where anybody else is, with these new regulations, it is a clean sheet of paper, and we don't have the benefit of an existing engine to learn from.
"From a cost cap perspective, that is a disadvantage, but then at the same time, we don't have the distraction of the current engine, reliability fixes and so on that are having to be dealt with there."
Horner, though, remains upbeat about his team's "impressive" progress so far, and is confident that they can continue hitting their targets before the 2026 season begins.
"We are only really going to see [what happens] in 2026, but we are meeting our targets at this point in time," Horner explained.
"With just under two years to run, if I look at the progress we've made in the last two years from a standing start, it has been very impressive.
"We don't even have any chassis rules yet, but if I was going to back any team to get the chassis right, I think we've got a reasonable track record.
"It is very bold what we've done, very brave and it is pretty ballsy, Red Bull wouldn't have won 117 races and done what we've done making bold decisions."