Le Mans 24hrs: meet the main contenders

The 2015 World Endurance Championship has opened with two compelling races this season, with Audi triumphing in at Silverstone and Spa with a chequered flag lead never bigger than 13.4 seconds. After six hours of racing on both occasions, that's monumentally close.

This week the sport has gathered at the crucible of endurance racing - Circuit de la Sarthe - for the most challenging event of the lot: The 24 Hours of Le Mans.

Audi, Porsche, Toyota and Nissan will all be vying for victory around the eight-and-a-half mile course in the LMP1 class, with the winning margin likely to be measured in seconds rather than laps

Here's how the quartet are shaping up for the weekend's day-long epic...

Porsche Team

Car
919 Hybrid

Drivers
#17 - Timo Bernhard (DEU), Mark Webber (AUS), Brendon Hartley (NZL)
#18 - Romain Dumas (FRA), Neel Jani (CHE), Marc Lieb (DEU)
#19 - Nico Hulkenberg (DEU), Earl Bamber (NZL), Nick Tandy (GBR)

Tech
The 919 carries the smallest engine of the main contenders - a 2.0-litre, four cylinder petrol - but it's boosted by an eight megajoule hybrid system for a total power output of around 900bhp.

The Porsche is also one of the lightest LMP1 contenders at 870kg; 30 kilos lighter than last year's model. This makes a significant difference when extracting the greatest range from the 68.5-litre fuel tank.

Prospects
With car #17 sporting a red and white livery - a reference to the 917KH that won Le Mans in 1970 - Porsche are as competitive now as they have been since their last victory at La Sarthe in 1998.

Performances have been getting stronger and stronger since their return to the LMP1 fold in 2014, the 919 delivering a victory in the WEC season finale in Brazil last November.

And the 919 proved itself the car to beat in first qualifying at La Sarthe on Wednesday evening, taking the top three spots. Neel Jani put the #18 car on pole with a lap of 3m16.887, the fastest qualifying lap since 1989 and a full three seconds ahead of the quickest Audi.

After a 17-year wait, is this the year Porsche will add a record 17th Le Mans winner's trophy to its (very long) mantelpiece?

Audi Sport Team Joest

Car
R18 e-tron quattro

Drivers
#7 - Marcel Fassler (CHE), Andre Lotterer (DEU), Benoit Treluyer (FRA)
#8 - Lucas di Grassi (BRA), Loic Duval (FRA), Oliver Jarvis (GBR)
#9 - Filipe Albuquerque (PRT), Marco Bonanomi (ITA), Rene Rast (DEU)

Tech
Audi have not been swayed in their belief that diesel remains the optimum fuel for endurance racing, with the R18 boasting a 4.0-litre V6 producing 550bhp.

After abandoning plans for an 8MJ hybrid system, the current 4MJ setup is still a category up from their 2014 car. It provides an additional 272bhp, with power harvested under braking and released through the front wheels.

Prospects
Having won Le Mans thirteen times since the turn of the millennium - not to mention the last five races on the spin - and on the back of successive WEC victories in 2015, Audi understandably start as favourites once more.

Fassler, Lotterer and Treluyer won this race together 12 months ago and have all the experience required to register back-to-back wins, the trio having already achieved the same feat in 2011 and 2012.

But they're not going to have it all their own way this year. The Audis could only manage positions 4, 5 and 6 in qualifying, indicating they're a little down on pace against VW Group stablemates Porsche.

However, Le Mans has always been as much about reliability and efficiency as outright pace. Audi remain the team to beat.

Toyota Racing

Car
TS0 40 Hybrid

Drivers
#1 - Anthony Davidson (GBR), Sebastien Buemi (CHE), Kazuki Nakajima (JPN)
#2 - Alex Wurz (AUT), Stephane Sarrazin (FRA), Mike Conway (GBR)

Tech
The brutal-sounding TSO 40 is powered by a 3.7-litre, naturally aspirated V8 petrol engine, with a 6MJ hybrid system bringing overall power into the 1000bhp region.

Two different versions of the carbon fibre composite bodies have been designed for the season, with the low downforce version in place for the Le Mans weekend.

Prospects
Perhaps not as strong as they'd hope. Toyota's technical director Pascal Vasselon has conceded that the performance advantage which saw the Japanese outfit win five out of eight WEC races in 2014 has disappeared entirely, but also believes it "is not the end of the world."

"We know that one second a lap is six and a half minutes over 24 hours," says Vasselon. "But last year the winning Audi spent 25 minutes in the pits."

It means that Toyota will have to focus on being on the right tyres at the right time, as well as doing everything to ensure their cars are reliable as possible over the duration of the race.

On Wednesday night, the Toyotas qualified in seventh and eighth, almost seven seconds down on the quickest Porsche. The fewer incidents their rivals suffer, the harder it will be for them to win.

Nissan Motorsports

Car
GT-R LM Nismo

Drivers
#21 - Tsugio Matsuda (JPN), Mark Shulzhitskiy (RUS), Lucas Ordonez (ESP)
#22 - Harry Tincknell (GBR), Michael Krumm (DEU), Alex Buncombe (GBR)
#23 - Olivier Pla (FRA), Jann Mardenborough (GBR), Max Chilton (GBR)

Tech
Nissan's approach has been radical to say the least. The GT-R's 3.0-litre twin-turbo V6 produces 550bhp, with another 700bhp of electric power - and it's all put through the front wheels. No, really.

And there's more. With the weight shifted forward, Nissan can afford to deploy 9-inch tyres at the rear as larger, 14-inch Michelins take the strain at the nose. This is a truly bizarre race car, one that could - in theory - entirely reinvent the LMP1 class.

Prospects
Or not. No one really knows what to expect from the Nismo, as it has barely turned a wheel in anger before this weekend.

Nissan missed Silverstone and Spa after failing an early crash test, meaning the GT-R reaches Le Mans all but untested.

Perhaps unsurprisingly, the GT-R was 20 seconds down on the fastest Porsche at the shakedown event a few days ago, and slower even than the quickest LMP2 at the end of a wet session. Darren Cox, Nissan's head of motorsport, has had to reassure fans that they will be "significantly faster" come race day.

But the quickest Nissan - Brit racer Jann Mardenborough's #23 car - could qualify only in twelfth spot on Wednesday, over 20 seconds shy of the lead Porsche. Le Mans is a notoriously unforgiving race, and it seems this year's event has come just too early for Nissan. Here's hoping they can defy the odds...