The verdict on WEC's LMP1 big guns

The three manufacturers that will slug it out for this season's World Endurance Championship titles are back on the grid at the Silverstone opener this weekend with new or nearly-new cars.

They have each undertaken significant development programmes for the new season: Porsche has built an all-new version of the 919 Hybrid; and Audi and Toyota have undertaken significant upgrades of their respective R18 e-tron quattro and TS040 HYBRID challengers.

Their only meeting so far, at last month's WEC official test at Paul Ricard, provided no clear conclusion on who has gained the most - which will make the events of Silverstone this weekend all the more intriguing.

TOYOTA

Toyota has yet to show its hand ahead of the start of the defence of its WEC drivers' and manufacturers' crowns. It ran through its programme at the Ricard test days and didn't seem unduly concerned that its latest TS040 HYBRIDs languished down in fifth and sixth positions on the timesheets.

The Japanese manufacturer has upgraded last year's championship winner in much the same way as Audi. It is labelling the 2015-spec car as "80 per cent new" and points out that the doors are the only items of bodywork carried over. What it hasn't done, unlike its rivals, is move up a megajoule class and it remains in the division that allows for 6MJ to be deployed around the long Le Mans lap.

The difference in hybrid punch might not be so different between the new 6MJ Toyota and the 8MJ Porsche on the regular circuits that host the six-hour WEC races where the amount of deployment is higher per kilometre than at Le Mans. Toyota has focused on hitting the 6MJ mark on all circuits, while Porsche says it might not make 8MJ everywhere.

Gains have been made aerodynamically with a reversion to the open-nose concept - in both high and low-downforce configurations - that it ran only at the first two races last year. It says there were greater advances to be made with this set-up than with the 'snowplough' front it ran at the Le Mans 24 Hour and for the remainder of the season.

There has also been a focus on improving the strong suit of the TS040 last year: the way it looked after its tyres. That is a consequence of new limits on the number of sets of tyres that can be used in the six-hour races.

Toyota isn't saying whether that will add up to enough for it to retain its position at the front of the WEC field. The reason is that it doesn't know and the answer might not become clear until deep in the WEC season.

Toyota Racing — Toyota TS040 HYBRID
#1 Anthony Davidson/Sebastien Buemi/Kazuki Nakajima
#2 Alex Wurz/Stephane Sarrazin/Mike Conway

AUDI

Audi has left no stone unturned in its overhaul of the Le Mans-winning R18 e-tron quattro, a car that was outgunned over the final rounds of last year's WEC.

It is not a new machine, in the sense that the monocoque has been retained, but the tub and the gearbox casing are the only carbon components carried over from last year's car.

A major upgrade of the aerodynamic package includes a reprofiled nose - which is why the front crash structure is new - and has yielded significant gains, while suspension changes have been focused on making the turbodiesel R18 work in all conditions. Last year, there problems getting the tyres into their operating window when conditions were cool.

Audi has also moved up, as planned, one megajoule class from 2MJ to 4MJ with an upgraded version of its existing single kinetic energy-retrieval system on the front axle. Even though the 4MJ gap to Porsche hasn't changed, Audi believes it will closer in terms of hybrid boost, working on the logic - questioned by some - that 2MJ is 33 per cent of 6MJ and 4MJ is 50 per cent of 8MJ.

The changes add up to a package that Audi Sport Team Joest believes will be more competitive over a range of circuits, though it suggests that there might be some weekends when its rivals still have the advantage if the Equivalence of Technology between diesel and petrol power doesn't change significantly at the next cut-off after Le Mans.

Silverstone, with a proliferation of fast corners, is most definitely not going to be one of those races. The high-downforce Audi should be in its element this weekend.

Audi Sport Team Joest — Audi R18 e-tron quattro
#7 Andre Lotterer/Marcel Fassler/Benoit Treluyer
#8 Loic Duval/Lucas di Grassi/Oliver Jarvis
#9 Filipe Albuquerque/Marco Bonanomi/Rene Rast*
*entered for Le Mans and Spa only

PORSCHE

Porsche might just have to be regarded as the pre-season favourite in LMP1, and not because it came out on top - and by some margin - at the Paul Ricard test. The reason is that it has most to gain from the position in which it ended last season.

Porsche was new to the game last year and has produced a car for 2015 that is all new, right down to its carbon monocoque. The second iteration of the 919 Hybrid is on the 870kg weight limit, down from last year's 900kg, and it has moved up from the 6MJ hybrid class to the highest 8MJ division.

They must combine to make an immediate gain in laptime that Porsche LMP1 technical director Alex Hitzinger says its rivals "will have to find somewhere else". The logic is simple: Toyota and Audi were already on the limit in 2014 and the P1 rulebook is framed to favour cars running in the highest hybrid class. He succinctly calls it "laptime in the pocket".

Then there is the weakness that prevented the 919 from being a contender over the second half of the season, at least before it arrived on the high-grip Interlagos circuit in November. The grippy asphalt masked the design's appetite for its tyres and allowed Porsche to take a historic first world championship endurance race victory since 1989.

So if the redesign has been successful in overcoming that tyre issue, then Porsche has made another significant gain that its rivals will find hard to match. The evidence suggests that it has, even if Hitzinger insists that "still work to do on long runs".

Factor in a likely dominance in qualifying thanks to the advantages of its hybrid system and that Porsche has a year under its belt as a race team, and it is difficult to imagine that the new 919s are not going to be contenders every time out in 2015.

Porsche Team — Porsche 919 Hybrid
#17 Mark Webber/Timo Bernhard/Brendon Hartley
#18 Neel Jani/Romain Dumas/Marc Lieb
#19 Nico Hulkenberg/Nick Tandy/Earl Bamber*
*entered for Le Mans and Spa only

NISSAN

Nissan isn't racing at Silverstone, nor at Spa at the beginning of next month. Its radical GT-R LM NISMO wasn't homologated in time to compete this weekend and the Japanese manufacturer took the decision to refocus on Le Mans, the race for which the front-engined, front-wheel-drive LMP1 was designed.

It was arguably a sensible decision from a manufacturer behind in the development of what is a complex racing machine. Yet it still has a lot of catching up to do in a relatively short space of time to allow it to achieve a stated target of qualifying in among its factory rivals when it arrives at the Circuit de la Sarthe.

When the GT-R LM does finally compete, it will not be in the form originally intended. The concept of the car calls for regeneration from the front axle and deployment via its skinny nine-inch wheels and tyres at the rear. It has opted to retrieve and deploy at the front axle, which explains its decision to run in the 2MJ and lowest hybrid sub-class in year one of the programme. The stated reason is one of weight.

Putting all the power through the front wheels will inevitably raise torque-steer and tyre-life issues, but the biggest question is whether the concept falls over like a house of cards if one of the key building blocks is removed.

Nissan Motorsports — Nissan GT-R LM NISMO
#21 Tsugio Matsuda/Lucas Ordonez/Alex Buncombe*
#22 Olivier Pla/Harry Tincknell/Michael Krumm**
#23 Marc Gene/Jann Mardenborough/Max Chilton
* races only at Le Mans; ** Krumm is confirmed for Le Mans only

THE BATTLE OF THE P2 COUPES

The Ligier JSP2 coupe, pictured, was the quickest LMP2 machine over the second half of last year's WEC in the hands of the OAK-run G-Drive squad, even if it ultimately lost out in the championship battle. This year it is joined by the new ORECA 05 and the long-awaited Strakka Dome S103.

It would be wrong to say that the Ligier moved the goalposts in the division because the previous generation of open-top machinery was still in the ball park, but it did have an advantage that will be readily apparent at a track like Silverstone. If the ORECA or the Strakka Dome are an advance on the Ligier, it will not so much ring the death knell for the open cars as screw down the coffin lid.

P1 PRIVATEERS

LMP1 privateer Rebellion misses Silverstone after deciding on the new engine for its eponymous ORECA-built R-One too late. Rear end revisions required to incorporate the twin-turbo AER V6 in place of the normally-aspirated V8 saw to that.

The intention is that the new engine will move it closer to the factory entries. That's a big hope indeed. given the advances made by the manufacturers for this season.

The ByKolles squad, formerly Lotus LMP, also uses the AER powerplant and has undertaken major revisions of its CLM P1/01, pictured, as it tries to get on terms with Rebellion in the privateers' battle. The 2015-spec CLM looks like a major step forward on the evidence of the Paul Ricard test, but it has a large jump to make.

NEW QUALIFYING

The aggregate qualifying system wasn't popular when it was introduced at the beginning of 2013, but it did provide enough excitement, particularly last year, to turn most sceptics. A tweak for 2015 should simplify it - the average is now calculated on the fastest lap set by each of two drivers rather than their best two.

It's probably not going to make much difference at the sharp end of the grid, but in GTE Am a further rule change demanding that the bronze-rated driver mandatory in each line-up must be one of the qualifiers undoubtedly will.