UPDATED AT 1925 BST
After months of drawn-out and occasionally bitter wrangling, Formula 1's switch to 1.6-litre turbo engines for 2014 was rubber-stamped on Wednesday by the FIA world council, the sport's legislature. In theory, that should be the end of the matter.
But it may not be that simple. It has emerged in the last few days that many of F1's circuits share F1 boss Bernie Ecclestone's concerns about the new engines.
He believes the ear-splitting screech of the current 2.4-litre V8s is a critical part of the spectacle of F1 and that the introduction of the new engines, which will have a different and probably more muted sound, will reduce the sport's appeal.
Those with long memories in F1 have raised an eyebrow about Ecclestone's new concern for trackside spectators. This is a man who, until this latest political battle, appeared to some observers to have an eye only for the TV audience, from where much of the sport's income comes.
The circuits, though, are a different matter. Because of their contracts with Ecclestone's companies, the only way they can raise revenue out of F1 is through paying spectators. Costs are high and margins are tight. So if numbers will fall, they have a problem.
The circuits had already expressed their concerns privately to the F1 teams and the FIA but their worries became public courtesy of an article in a Sunday newspaper.
It claimed all the tracks apart from China and Korea had signed a letter to the FIA saying they would consider dropping F1 in favour of IndyCars if the new engines were adopted.
The story appeared in a newspaper to which Ecclestone often speaks, was written by a journalist who has close links with him and featured quotes from Ron Walker, chairman of the Australian Grand Prix Corporation, who, you guessed it, is close to Ecclestone.
Neil England - the non-executive chairman of Silverstone, who deals with Ecclestone regarding the British Grand Prix - described the report as "a slight misrepresentation of the situation". Silverstone had not, he said, been signatories of any letter but they had made clear their discomfort about the new engine rules.
England does, he says, see the "media value" of the new engine - Ecclestone himself has described it to me as "PR" - but says he would prefer to focus on the "things that make a difference".
He agrees that the noise is a large part of F1's spectacle and, while Silverstone support attempts to reduce F1's carbon footprint, they feel a bigger impact could be made in other ways, such as producing co-ordinated travel plans for spectators and teams.
England denies he has been lobbied or manipulated by Ecclestone. "He's concerned and has an awareness that it's a potential issue," England says. "I don't feel manipulated and I don't think that's what happened."
Someone on the other side of the argument had a succinct response to that. "Of course they've been pressured by Bernie!" he said. "They've read all his nonsense about engine noise for weeks and weeks and weeks!"
As I said, the argument has got a bit heated.
The new engines were the brainchild of the F1 teams and they have been enthusiastically embraced by FIA president Jean Todt - with whom, incidentally, Ecclestone does not see eye to eye.
The idea behind them was two-fold:
- to popularise and make 'sexy' a direction road-car manufacturers were already heading with their engines
- and to insulate F1, in a world of diminishing fossil fuels and climate change, from charges that it was wasteful by playing a role in the increased development and sales of more efficient road cars.
The idea is that, by using these engines in F1, the public will increasingly understand that an exciting car can have an efficient, small capacity engine and regenerate as much energy as possible. In addition, it will speed up the development of the technology by exposing it to the white-heat of F1 competition.
Those in favour of the engines, then, say that to dismiss the new rules as having only "media value" somewhat misses the point.
It may be true that persuading spectators to get more buses and trains to a grand prix rather than driving their private cars would reduce carbon emissions more effectively than changing the engines in the F1 cars themselves. But it could also be said that if a significant proportion of the world's car users switched to more efficient vehicles, the effect of that would be exponentially larger again.
Those backing the new engines counter the arguments about noise as follows:
- F1 previously used turbo engines of almost exactly the same size as those being introduced in 2014 back in the 1980s (1.5-litre turbos as opposed to 1.6-litre turbos). No-one complained about the noise then. In fact, that time is remembered as a golden era.
- Audi and Peugeot use turbo-diesel engines at the Le Mans 24 Hours sports car race and have done for several years. These sound infinitely less dramatic than the new F1 engines will do - they are diesel, for a start, and they rev much lower - but spectator numbers at Le Mans haven't reduced. The event still attracts around 250,000 people.
- Many of the 'rebels' are old romantics who hark back to the glory years of the 1970s and the sounds of some of the engines used then. But they forget that the supposedly evocative Matra V12 and Ferrari flat 12 revved to no more than 12,000rpm, exactly what had been the initial limit imposed on the new turbos.
- No one knows whether spectators will object to the sound of the new engines because no one knows what they will sound like. That's because they haven't been in a car yet.
Following the intervention of the circuits, the rev limit of the new engines has been raised from 12,000rpm to 15,000rpm.
According to someone intimately involved with the negotiations over the new engines from the very beginning, this was done in response to the concerns about the noise, "even though we were quite confident that the sound was not going to be anything like as bad as most people feared".
It remains to be seen whether this will assuage the concerns of both the circuits and Ecclestone, although the fact England called for a "period of consultation" suggests not.
But there are many in F1 who believe Ecclestone is devoting his energies and concerns in the wrong direction.
As Mercedes team principal Ross Brawn put it: "There are many considerations we have to make when we are changing the power-plant in F1. Obviously the technology in the automotive field is changing and the big question is how relevant do we need to be and how relevant do we want to be?
"The technology we're working on with these new engines is the technology that is going to become commonplace in road car engines in the future: small capacity, turbocharged engine, direct injection, special Kers systems.
"We don't want to end up as a dinosaur in five or 10 years."