Meet the 2015 Le Mans contenders

This June, Porsche, Audi, Toyota and new contenders Nissan will descend on the Circuit de la Sarthe to compete in the 83rd running of the 24 Hours of Le Mans.

But last weekend saw the much-anticipated pre-fight weigh-in at Paul Ricard, each team pulled the covers from its 2015 LMP1 contender, before the cars hit the track together for the very first time in an official test session.

Well, everyone apart from Nissan, that is. The baffling Nissan GT-R LM Nismo wasn't in attendance, as the team behind it remained stuck in the workshop, attempting to make sure the bonkers 1250bhp, front-wheel-drive LMP1 racer is race ready and competitive for its debut at Le Mans.

The current crop of top-flight LMP1 racers are the pinnacle of going really bloody fast, really efficiently for a really long time. But all four main LMP1 players take completely different approaches to answering that brief. Which one will work best? Nobody knows, but that's what makes the race fascinating.

What we do know is that, after the two-day test at Paul Ricard, the ball is currently in Porsche's court. The 919 clocked the fastest times in every session over the course of the official World Endurance Championship test.

But there's plenty of time for the others to catch up before Le Mans in June, so click forth and choose your favourite flavour of LMP1.

As a retro throwback, Porsche has decided to splash one of its three 919 Le Mans cars in red and white for the occasion. It's a nod to Porsche's first outright winner of the 24 Hours in 1970, the 917KH driven by Richard Attwood and Hans Hermann.

As last year, the 919's hybrid system works in tandem with a diddy 2.0-litre V4 turbo petrol engine, sending over 500bhp to the rear wheels, while chunky electric motors feed the front.

But thanks to some development of the hybrid system, there's also been a big hardware shift. The 2015 919 has graduated from the six megajoule hybrid class to the top-level eight megajoule class. In human speak, that means that the 919 harvests more energy than last year, energy is stored on board and used by the hybrid system to power the car for longer and more frequently per lap than before.

The 919 still utilises last year's energy-retrieval systems that harnesses kinetic energy from the front axle - as well as the exhaust gases - but now returning the equivalent of 400bhp. This is stored in a water-cooled lithium-ion battery system until required.

The new 919 has lost weight too, now tipping the scales at 870kg.

It's not just Porsche moving up the megajoule ranks. German rival Audi has also seen a promotion, hopping from two megajoule to the four megajoule sub-category.

The new R18 e-tron quattro has been heavily revised, with only the chassis and gearbox casing carried over from its predecessor.

The front laser beam headlights have shrunk to make room for two gaping air intakes. This is just one part of a new aero package that sees a shorter, tapered rear end and more aggressive side pods, to increase cooling and make the prototype even slippier through the air.

It's built around the same monocoque as last year's Le Mans winning car, so has a single front-axle kinetic energy-recovery system and mechanical flywheel battery to store the ‘free' energy.

The bump up in megajoules means that Audi's pilots now have the equivalent of 272bhp to use at the front axle - but now for longer and more frequently than before. When the juice at the front axle runs out, it's the 558bhp four-litre turbodiesel V6 engine that'll get them round the rest of the lap.

In Toyota's own words, the second-gen TS040 Hybrid is ‘no revolution but it's an evolution almost everywhere.'

The WEC champions are sticking in the middling six megajoule class, utilising revised energy recuperation systems and a naturally-aspirated 3.7-litre V8. Combined, that hybrid powertrain is good for 1000bhp.

The main changes are under the skin, where the suspension has been modified to optimise tyre grip, while weight has been shed and the aero and crash structure tweaked. No doubt the petrol-electric racer will still sound awesome. Wrap your ears around this, kids.

Try as we might, we still can't quite get our head round Nissan's mind-boggling hybrid. Put as simply as possible, this is a 1250bhp front-engined, front-wheel-drive fruitcake of a car.

For the lowdown on this mad LMP1, click these blue words to get the tech explanation from Ben Bowlby, the genius who designed it. But if you want to know what it's like to drive, click these ones.

Due to failing an early crash test, the LM Nismo won't, as planned, make its racing debut at the WEC opener at Silverstone in two weeks' time. It won't make it to Spa on 2 May, either, as the team is focusing its efforts on getting as much testing done as possible before the main event: Le Mans, on June 13...