The Audi R18 e-tron quattro has a racing weight of 1,918 pounds, making it the lightest prototype they've ever built. This is how they do it.
The Audi team could lose a hundred pounds compared to last year thanks to the even more extensive use of carbon fiber reinforced plastic (CFRP) and the optimized design of metal parts despite the new regulations that would normally lead to an increase in weight. I believe Colin Chapman would approve that welding.
All the prototype's side panels are now required to be made of Zylon in order to protect the driver in the case of lateral impacts. If you didn't know, Zylon is a material that has a tensile strength 1.6 times stronger than that of Kevlar. There are also eight wheel tethers which are to prevent the separation of the wheels from the car in case of a crash.
The 2014 cars also have a rear crash absorbing structure similar to the one in the nose of F1 cars. It doesn't look like much, but it sucks up energy like a black hole.
Audi claims these new features would normally mean a gain of 44 pounds, but thanks to even more carbon fiber components and a complete redesign of all the tiny details and metal parts on the car, they managed to shred weight instead to further improve efficiency.
Let's hope they got enough downforce as well so they won't fly away either.