June 13, 2015 06:15 CET
(Bloomberg) -- Audi’s R18 e-tron Quattro has won the Le Mans LMP1 race every year since the new hybrid powertrain rules were established in 2012, but this year it will face a stiff competition from Porsche, Toyota, and Nissan.
The LMP1 category stands for Le Mans Prototype Top Tier, and it is made up of experimental vehicles that exist on the blurry forward boundaries of racing technology. All the cars must contain highly efficient hybrid propulsion systems, including electric motors, engines, batteries, and regenerative energy storage systems. But because of the broad rules within the vehicle class, teams are given extremely wide parameters in designing everything from their powertrain to the design and appearance of their cars.
"Different manufacturers have gone in different routes with regard to engine size, gasoline, or diesel power, turbo vs. normally aspirated, and the style of their energy recovery systems [ERS]," said Calvin Fish, a Fox Sports announcer and former racecar driver. "But despite this, the racing is close."
The 24 Hours of Le Mans race, which will begin today, is not only the longest-running endurance race in the world having taken place annually in France since 1923, but it is also one of the world's most thrilling and challenging.
Teams must balance a need for all-out speed and agility with a car's (and drivers') ability to perform at peak capacity through a full day of racing in what is often unpredictable and inclement spring weather.
On top of this, four different classes of vehicles compete simultaneously, hosting wild power differentials and levels of driver experience: Consummate professionals blend with wealthy amateur gentlemen racers.
And, for the first time since 1999, four different consumer vehicle manufacturers are participating in the race.
Audi’s R18 e-tron Quattro
Audi’s R18 e-tron Quattro uses a unique midmounted, turbocharged, direct-injected V-6 diesel engine to power the rear wheels, coupled with an electric motor powered by batteries and the massive energy produced during braking to send additional power to the front wheels, for all-wheel-drive capabilities under full acceleration.
Nissan GT-R LM Nismo
Nissan enters the field at Le Mans this year with an all-new car based on a radical design. In a complete break with tradition, it has its engine, a twin-turbocharged, gasoline-powered V-6 unit, up front and driving the front wheels. Energy captured during braking can be delivered to add more power to the front wheels, or it can be sent to the rear wheels. The front-engine, front wheel-drive setup allows the car to be impossibly low, and gives it an almost comically long nose and profile. Because more weight is over the front wheels, the front tires are significantly wider than those at the rear. The compact placement of the engine and drivetrain up front, allows for intense aerodynamic engineering, with the entire sides and rear of the car essentially being hollow to add downforce to the rear, which lacks the weight of a traditional mid-engine race car.
Porsche‘s 919 Hybrid-1
Porsche‘s 919 Hybrid-1 race car ups its efficiency this year, mounting an even smaller, turbocharged engine behind the driver, using an atypical V-4 design that sends power to the rear wheels. But the real news is its use of an eight mega-joule energy recovery system, which can store massive power in the bigger battery pack and provide an amazing amount of electric boost when needed.
Toyota WEC TS040 Hybrid-1
Audi may have won Le Mans last year, but Toyota won the entire World Endurance Championship (WEC) series, of which Le Mans is simply one race. And it did it, interestingly enough for the inventor of the world's most popular mass-market hybrid the Prius, with the largest engine of any of its competitors, a throaty 3.7 liter gasoline-powered V-8 unit with no turbochargers. Of course, as per the rules, Toyota's car also uses a hybrid energy recovery system, but it sticks with the midrange 6 mega-joule option. Two electric motors provide assist, one helping the engine with the rear wheels, and the other providing all-wheel drive capabilities by powering the front.