Formula One voted last week to move to smaller turbo powered engines from 2014 - but how will the new designs change the cars and will it make the sport more attractive for manufacturers again?
Turbo engines were banned in F1 in 1989 and since then a number of differently sized normally aspirated units have been run, first a 3.5-litre, then 3-litre and, since 2006, the standard 2.4-litre V8 design used currently by all engine manufacturers.
The fixed engine format has proved to be a cost-effective solution, with limited development allowed year on year, and a move to a new formula will come with great expense. But the manufacturers have driven the change, demanding the sport reduce engine size to become more relevant to the automotive industry as road car engine designs become more and more efficient.
Initial plans to go for an in-line four-cylinder layout in 2013 proved too extreme, so the engine bosses have settled on a compromise to introduce a new format one year later, in 2014, with a V6 1.6-litre turbo limited to 15,000rpm, with one turbocharger, controlled fuel flow and an increased amount of energy recovery.
So, what does that mean for F1's future?
POWER, EFFICIENCY AND DURABILITY
The aim of the new regulations is to create engines that develop the same amount of power but more efficiently - and that will be done by a reduction in volume, the addition of a restricted turbo and the introduction of a fuel flow limit.
The decreased volume of the V6 unit compared to the V8 would naturally reduce the amount of power attainable, but an unrestricted turbo would increase it beyond what it is now. Restrictions both the turbo boost levels and the amount of fuel available per second, however, are specifically designed to limit the engine to around 600hp.
The current units run at around 750hp, and the regulations then aim to generate the additional power through increased energy recovery - both via KERS (which will increase from 60kw to 120kw) and from the new turbo technology of exhaust recovery.
Overall, it is understood the aim is to cut fuel expenditure to 65 percent of the amount used in each race this year (which is estimated at between 175 and 180kg) and engineers will have to work hard on reducing internal friction to improve engine efficiency.
Meanwhile, the FIA have stated a durability target of 4,000km per engine, which compared to the current lifetime of around 2,200km per unit means that the amount of engines used per year could drop to around four or five for each car.
The chassis regulations that were due to come in for 2013 were based around the smaller four-cylinder engine concept, with some radical aerodynamic tunnel underbody solutions intended to maximise downforce from ground-effect.
In May, however, these concepts had already been tamed down and with the larger and wider v-shaped engine, the amount of scope for this will be further reduced - meaning the chassis regulations will have to be further developed to match the new engine concept.
One important design challenge now eliminated, however, is that of the engine as a stressed member of the chassis. Adrian Newey recently said that the four-cylinder turbo is "not a nice engine to install" as it cannot be a fully structural part of the car and would need additional support. The V6 unit, however, is strong enough to work structurally in the same way that the current V8 units do.
The sidepods and internal sidepod layout is also likely to see some significant changes, as the cooling requirements for the V6 turbo engine will be significantly different to the current V8 units. Also, the air intake above the drivers head is designed to pressurise air flowing into the engine as well as feeding air to cooling elements, but with the turbo V6 there will be no need to provide this pressure, meaning roll hoops could open up and engine covers be lowered.
The switch to the V6 engine still seems some time away (and plenty could still change!) but the 2014 season is only two and a half years away, and some teams will be beginning to develop overall car concepts for that season as early as late-2012.
The switch in engine regulations already comes after most manufacturers had committed resources to conceptual development, with Renault (the most staunch supporters of the four-cylinder unit) claiming to have spent around £10m already.
Ferrari pushed hard for the V6 as it is more relevant to their sports cars, whereas Renault is more efficiency-driven and even the likes of Mercedes are working towards smaller engines for their road cars, with most road car engines in 2014 expected to be reduced volume.
Ross Brawn made a good point in his recent comments on the situation, explaining: "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 current V8 normally aspirated engine is seen as a rather antiquated concept, while the four-cylinder, while much more aligned to road cars, is, for many, just was not what Formula One is about.
The V6 compromise of smaller engines with turbo power and integral KERS systems is middle ground, and compared to current specs it speaks much more to the kind of manufacturers that Formula One is trying to lure back into the sport.
And if, as suggested, there is a resource restriction on development of these new units, new manufacturers could be enticed by the challenge of innovative engineering at a fixed budget - especially with the extended 2014 deadline giving them more time to develop.