The futuristic design of the new R18 will no doubt unleash emotions but the most important feature of a racing car is its speed. That’s where aerodynamics play a key role. To put things very simply, to move, you produce energy to push against the force of the air around you. Imagine walking with a strong wind against you – it takes a lot more effort than when there is no wind. It’s the job of the aerodynamics engineers to try to limit the resistance created by air, to increase the speed at which the car can travel. If the air can be channelled away, it doesn’t hamper progress, which is why the new R18 has a very thin nose.

The proportions of the R18 have been altered to improve aerodynamics and to even out weight distribution. Just as truck drivers spread the load to avoid unbalancing their trailer, racing car designers make sure weight distribution is even and also avoid any excess weight. At 875 kg, the new Audi is at the minimum stipulated for its class.
A lighter car also requires less fuel, a necessity for LM P1 hybrid prototypes since the new regulations stipulate a lower fuel allowance and smaller tank (49.9 litres for diesel engines). Thanks to the lithium-ion battery and the design of the diesel engine, the new lighter Audi R18 will use almost a third less fuel during this year’s 24 Hours of Le Mans compared to 2011 and half as much as in 2006.

This efficiency doesn’t affect the car’s ability to accelerate: the engine’s torque remains at over 850 Nm and the hybrid system stores energy recovered from braking in the lithium-ion battery, which the driver uses when in need of extra power. This year, Audi will be recovering six megajoules of energy, compared to four last year and two in 2012 when the constructor was the first to win the 24 Hours of Le Mans with a hybrid car. The regulations allow for a maximum of 8 megajoules and both Porsche and Toyota will reach that limit this year. In 2012, the Motor Generator Unit (MGU) that transforms the energy provided the Audi with 150 kW of extra power. Today’s car boasts an extra supply of 350 kW, although the limit for the 24 Hours of Le Mans is 300 kW.

The ultimate aim of Jörg Zander and his team of engineers is to produce a fast, reliable car and they are constantly seeking different means to achieve that goal, such as the suspension system on the new R18. However, safety is also a major concern right from the design stage. Audi has introduced revolutionary tyre pressure sensors, LED headlights and rearview cameras — technology that is used on many road cars today. Indeed, since the first race in 1923 the 24 Hours of Le Mans has been a testing ground for the features we take for granted on our everyday cars.
 

Cécile Bonardel / ACO - Translated from French by Emma Paulay