In the 991 series of the 911, which was introduced in 2011, Porsche has further perfected lightweight design for sports cars. It achieves a number of goals: improving vehicle dynamics while reducing fuel consumption, as well as enhancing safety and raising levels of comfort in comparison with earlier vehicles. The engineers chose a concept which puts the right material in the right place, using the right construction method. The current vehicle generation is therefore lighter than its direct predecessor for the first time, by approximately 40 kilogrammes. And this despite the additional weight originally expected due to the longer wheelbase, the more stringent safety requirements and the enhancements to the overall package. The largest proportion of the weight saved (around 80 kilogrammes) was due to the new body-in-white with mixed aluminium-steel construction. With the exception of local reinforcement parts, the front body section and large parts of the floor and the rear section are made of aluminium. This is also true of the lids, wings and the door structure. The coupé is 44 per cent aluminium and the cabriolet 43 per cent. A significantly larger proportion of the steel parts are made of super high-strength and ultra high-strength materials. The hot forged, press hardened steels provide a particularly high degree of occupant protection. The intelligent mixed aluminium-steel construction also changed the production process at the Zuffenhausen plant. While resistance spot welding was the dominant production method in the age of steel bodies, today’s mixture of materials requires different joining processes. And this with up to 400 individual parts which a body-in-white is made up of. The key areas are the many steel and aluminium joints – they cannot be welded. The increased use of structural adhesives, which also prevents bimetallic corrosion between the two materials, is one solution. However, new mechanical joining processes are also used, such as clinching, punch riveting and friction drilling. The ideal joint is selected in each case.