November 18, 2005 The turbocharger , which has dominated the development of the internal combustion engine for the last 30 years, turned 100 years old this week. On 16 November 1905 Swiss engineer Dr. Alfred Buchi received patent No. 204630 from the Imperial Patent Office of the German Reich for a machine consisting of a compressor (turbine compressor), a piston engine, and a turbine in sequential arrangement. Porsche chose the occassion to introduce its very latest take on the turbocharger, this time with variable turbine geometry (VTG). This extensive article covers the development and major achievements of the turbocharger and the new VTG technology which realises even more efficiency, resulting in a significant improvement of engine flexibility and acceleration particularly at low engine speeds. In introducing the new 911 model some 31 years after it gave us the first series production sports car with an exhaust gas turbocharger (the 1974 Porsche 911 Turbo), Porsche will be presenting the world's first turbocharged gasoline engine with variable turbine geometry (VTG). The core features of VTG are the variable turbine blades guiding the flow of exhaust gas from the engine in exactly the direction required on to the turbine wheel of the exhaust gas turbocharger. The principle of variable turbine geometry thus combines the benefits of a small and large exhaust gas turbocharger all in one, with the combination ensuring both very good response and high torque at low engine speeds as well as superior output and high performance at high speeds. And the supreme level of torque is now maintained consistently throughout a much wider speed range.