First flagged by FIA president Mohammed Ben Sulayem, the notion has gathered steam in recent weeks.
On Wednesday, a report in Germany claimed the idea could even be accelerated into 2028 with the championship retaining its current power units until then.
For 2026, F1 will increase its reliance on electrical energy, with half of the car’s power coming from the hybrid unit.
It’s a choice that has seen Audi, Ford, and General Motors all buy into F1, but at the cost of expensive, complicated, and heavy engines.
There is also a concern that the new regulations will introduce greater disparity among manufacturers and could negatively impact the on-track show.
“There’s a lot of debate about the future,” Horner admitted.
“We’ve got a set of regulations for next year, in ’26; I think there’s some limitations to those.”
In addition to the power unit changes next season, F1 will introduce new chassis regulations.
That includes the use of moveable wings, a design necessity amid concerns the reliance hybrid power would see cars run out of energy on a long straight and force drivers to downshift.
To address that, moveable wings will be introduced to reduce aerodynamic drag in a straight line while affording them higher corner speeds – there was a worry that the new F1 machinery would corner slower than F2 cars.
“We’ve ended up in a situation where the chassis is having to compensate a huge amount for perhaps the shortcomings of the split in electrification and combustion,” Horner pointed out.
But with testing for the 2026 season set to begin in January, it leaves precious little time for any meaningful change to be made now.
On top of the technical implications of backing out of the current plan, there is a commercial element to it too.
Honda, for example, will switch from Red Bull to Aston Martin, while Alpine will stop producing its own power units in Viry in favour of a Mercedes supply.
Audi currently uses Ferrari units, which will go to Cadillac, as the German manufacturer develops its own engine and transforms the Sauber operation in its own image.
“I don’t really see how you can unwind what’s in place because of all the different power unit changes that are happening,” Brown observed.
“I’m not sure how you put the genie back in the bottle.”
In addition to an increased reliance on hybrid power, the 2026 package includes a switch to sustainable fuels.
It’s that point that opens the door to F1 reverting to high-revving, screaming normally aspirated engines.
“It’s quite a romantic idea,” said Alpine boss Oliver Oakes.
“It does sound quite good for Formula 1.”
The use of sustainable fuel in normally aspirated engines offers a number of key benefits.
From a fan’s perspective it will ramp up the visceral experience after more than a decade of droning hybrid power.
Moreover, the simplicity of a V10 design, or something similar, is attractive as it broadens the market of potential suppliers.
That’s important as, while F1 is currently enjoying a boon as far as manufacturer interest goes, that could evaporate just as quickly.
Should that happen, it could leave a vacuum of available power unit manufacturers given the cost and complexity of the current designs.
There’s also a sporting impact, with normally aspirated engines smaller and significantly lighter than the current power units, translating into smaller, mor nimble cars – an FIA catch cry of the 2026 regulations.
“A screaming V10, so long as it’s done responsibly with fully sustainable fuels is hugely attractive,” Horner noted.
“The big question is when would that be for, and what is the game plan between where we sit today and then?”
Horner’s comments carry weight as leads the transformation of Red Bull from a customer team into an OEM.
He founded Red Bull Powertrains, which has since partnered with Ford in developing its 2026 power units, an investment that is difficult to walk away from.
McLaren is less hamstrung given its position as a customer of Mercedes HPP.
It affords Brown a different perspective, arguably one with less vested interest, though Horner did underscore his support of a move back to V10 engines.
“It would be a massive departure to move away from what is currently being worked on very hard for 2026,” he opined.
“From the fan in me, the concept of a screaming V10 engine would be very exciting for the sport.”
Brown shares that opinion, noting McLaren has the advantage of being able to simply go with the flow and race whatever it is given.
“Formula 1’s always been a very technical challenge when you have new regulations,” he said.
“This is no different. For ’26, we’re happy and ready to race, and ready to race whatever the rules may be.
“I think a V10 definitely, as Christian said, would be pretty cool with sustainable fuel.
“But it is a bit of a head-scratcher of how you would put that in place if you did want to make a change.”