F1's engine row decoded: The power play shaping Formula 1 explained
Proposed changes to the engine regulations for 2021 and beyond have prompted Ferrari to warn they could leave Formula 1 and opened up clear battle lines in the paddock.
Sky Sports looks at why the row has broken out and what might happen next...
Why has the row broken out?
While the fight currently brewing in the paddock is ostensibly about F1's power units post-2020, it runs much deeper than that.
The current power-play is Liberty Media's first big test since purchasing the sport a year ago and merely the tip of an iceberg.
As one team boss put it in Brazil, F1 is currently at a "crossroads". The Concorde Agreement, which shapes the sport's regulations, runs out in 2020. Finalising F1's engine for 2021 and beyond is only the first step in determining the sport's future direction. The even-thornier issues of cost caps and cash distribution are next on the agenda - and that's where the problems really might begin
Fundamentally, the question being asked is whether Formula 1 is a sport, entertainment or technology showcase.
And there are plenty of different answers to that conundrum being given.
And what's Liberty Media's position?
Liberty find themselves in a delicate balancing act. After a positive and popular first 12 months in charge, F1's new owners are now attempting to tread a fine line between pacifying the sport's current engine makers while also making F1 more attractive to new entrants and fans.
In a concise snapshot of Liberty's outlook, chief executive Chase Carey explained last week: "We want teams to compete to win, but we want all the teams to have a chance."
But whether it's possible to please everyone at once remains to be seen.
How divided is Formula 1?
That depends on who you speak to. While F1's 'have-nots' want the sport to be more equal and played on a level field, the 'haves' are naturally determined to protect their territory and see F1 remain a survival of the fittest - in which they, inevitably, prosper.
The battle lines aren't currently clearly defined. But anyone envisaging the sport split into two camps, with the engine manufacturers - Ferrari, Mercedes, Renault and Honda - grouped together in one and the remaining independent teams - headed by Red Bull and possibly including McLaren - in the other, probably wouldn't be too far amiss.
What exactly has been proposed so far?
F1's engine manufacturers - both current and potential - met with the FIA and Liberty Media in Paris at the end of October to discuss F1's engine plans post-2021.
Boiled down, the proposal put forward would see F1 powered by a single V6 turbo engine without the MGU-H hybrid element.
While the MGU-K would be made more powerful, there would also be a degree of 'standardisation' around the energy store and control electronics.
And what difference would that make?
The plans were wrapped around an "intention to reduce costs while maintaining road relevance with hybrid technology and improving the sound of the cars and the appeal for the fans".
But there is, inevitably, more to it than just that.
By reducing costs and complexity, the sport's owners hope to bring the field closer together to make F1 even more attractive to fans and potential new entrants alike.
According to Carey, "Sports are built on the unexpected". But since the current hybrid engines were introduced at an extravagant cost in 2014, only Mercedes, Ferrari and Red Bull have won an F1 Grand Prix. And this season, Lance Stroll of Williams is the only driver outside of the 'big three' to reach the podium in any race.
And what's the problem with the new proposals?
The four-engine manufacturers complain that removing the MGU-H - which retrieves energy from the turbo - means they would have to design a brand new power unit at considerable cost having previously spent a small fortune developing the sport's existing power units.
As Mercedes chief Toto Wolff told Sky F1 in Brazil: "In the meeting, besides the things we agree on, suddenly there were five new ideas of 'let's do this, why don't we do this?' and we said 'no' because this would mean three years of parallel development of engines."
And then there was the headline-grabbing response of Ferrari.
"Formula 1 has been part of our DNA since the day we were born," Ferrari president Sergio Marchionne said. "But if we change the sandbox to the point where it becomes an unrecognisable sandbox, I don't want to play anymore."
How seriously is Ferrari's quit threat being taken?
Reaction to Marchionne's warning has been mixed. Ferrari have threatened to leave F1 on numerous occasions in the past but remain the sport's only ever-present outfit.
"They'll bluster that they don't need F1 but what other form of motor racing is going to give Ferrari the platform that F1 does?" responded Red Bull boss Christian Horner pointedly.
But there is a potentially-critical difference between Ferrari's current warning and those of the past. In spirit, if not degree, Mercedes appear to be aligned with F1's most famous team in unhappiness at the vision being presented for F1's future.
This weekend, Mercedes chief Niki Lauda was quoted saying: "I'm worried. You are a fool if you think that to make grands prix more attractive you need to have a different winner every weekend. F1 is about competition."
What happens next?
All we've heard so far is a debate about F1's power unit post-2021. Next on the agenda is likely to be a plan to introduce a budget cap as well as improve the look of F1's next range of cars. After that, it's income distribution - will Ferrari continue to play ball if their payments, swelled by a 'heritage payment' reputedly worth $70m in 2016, is reduced or even abolished? And you thought they reacted badly to the power unit plans...
As Williams' Paddy Lowe put it with considerable understatement in Brazil when merely reflecting on F1's engine proposals, "It's a difficult problem to solve."