The momentum accrued by the FIA WEC since the inaugural season in 2012 has been one of the true feel-good stories of professional motorsport in the present decade.

The regulations, strength of the grid, quality of drivers and teams have been key to the renaissance at the peak of global endurance racing. For this, the ACO, Gerard Neveu and his team, and also the FIA must all take considerable credit.

While 2016 is likely to see some bumps along the way, particularly in the crystallisation of the 2018 technical regulations, there is again positivity searing through the manufacturers and teams as they ready themselves for what promises to be an even more incendiary fight for on-track supremacy.

In each of the three primary LMP1 manufacturers – Porsche, Audi and Toyota, there is much to whet the appetite.

Porsche is chasing further improvements in its proven package, as the Weissach marque looks to start a new modern epoch to rival its 1980s heyday, and equally sister manufacturer Audi wants to eradicate the memory of a valiantly fought, yet ultimately unsucessful 2015 campaign.

Toyota meanwhile is uncharted territory with a completely new design for 2016, its potent technical capabilities in Cologne working overtime as the operation strives to atone for the bitter trouncing it took last season.

Here's what we can expect from the three grandee squads as battle gears up to recommence at Silverstone in April.

Porsche

Deserving champion and last term's development king, Porsche now has a big target on its back. Audi and Toyota are taking aim, but if 2015 is anything to go by, there will need to be some "dead eye" marksmen in both their design offices next season.

Led by a master of incremental technical development in Alex Hitzinger and the organisational savant that is Andreas Seidl, Porsche does not have an acknowledged weak link heading in to its first title defence for 30 years.

Enhancement will be the order of the day for 2016, when Porsche gets its wheels down at Silverstone in April. The 919 has been continuing a spectacular development curve throughout the last six months, with tests frequently occurring, even between the flyaway events at Fuji and Shanghai last autumn.

That test, at Monza, saw Timo Bernhard put significant miles on a revised front suspension, one of the areas that Porsche has targeted for key gains in 2016.

Further trials took place at Barcelona in November, before a more extensive outing at Aragon last month, where engine, electrical and hybrid mods were worked on.

Not even Hitzinger knows how much additional window of further enhancement there is on the 919. Progressively, the Stuttgart-based marque is discovering how much more it can extract from its multi-title winning package as it continues to gather the miles.

But Porsche will have to call upon all its engineering spedigree to ward off the more revolutionary new Audi R18 and the all-new Toyota TS 050. The prospects of whether it can or not for the whole season will be the defining topic of 2016.

Audi

What is new for Audi in 2016? That’s an easy one - everything. The 2016 spec R18 e-tron quattro looks like a new breed and it absolutely is.

From the bold aerodynamics, including an eye-catching raised nose section, to the upgrade from the 4MJ to 6MJ energy retrieval sub-category, Audi has done everything within its power to catch the Porsche 919 in 2016.

Audi didn’t have a bad 2015 season, but two wins from eight events was simply not enough for the most decorated outfit in recent sportscar history.

2016’s model really started in 2013 for Audi, with initial concepts beginning in November of that year. The first CAD designs started churning out of the design office in the summer of 2014. That is a detailed gestation, and one that saw the early birth with the car testing this autumn.

Overseen by Jorg Zander and Wolfgang Dieter Appel, the development phase is already in full swing. As well as the leap to 6MJ for the turbodiesel challenger, the switch to lithium-ion batteries as opposed to the flywheel storage system sees the most far-reaching changes for Audi in many years.

Initial feedback from the drivers indicates that Audi’s quest for revenge is very much on target.

Toyota

You could almost see the pallor of senior Toyota executives wash out across their faces after the Silverstone opener last spring.

That is all history now, and Toyota Motorsport should be commended for reacting quickly and decisively. Immediately after the second round at Spa, last May, senior management were up-front and clear that its 2016 program would be brought forward with increased speed and focus.

This was exemplified by the decision to accelerate the development of the new compact V4 turbo powerplant for use this year, which was originally intended to race in 2017.

All this has naturally ensured that the TS 050 will initially be behind the testing curve compared to its rivals, but with three months until the first group test at Paul Ricard, to be held over the Easter weekend, Toyota has time to at least understand and strategise the many changes it has been forced to deploy with haste for 2016.

Toyota will retain its double KERS configuration with both axles retrieving energy this year. Motorsport.com understands that the new aerodynamic package for the TS 050 will include some visually interesting concepts when it runs for the first time in the coming weeks.

Kamui Kobayashi is likely to be confirmed as Alex Wurz’s replacement in Tokyo next month. The chief hopes of the marque, however, are likely to lie with the powerful axis of Buemi-Davidson-Nakajima, who should be worth watching - particularly in the second half of the season, when maturity for the new package is likely to be reached.