There was also some speculation that the engine block of the original 5.0 litre Lamborghini V10 is closely based on the Audi 4.2 FSI V8, which Audi produces for their luxury cars. However, this was denied by AUDI AG, in their official documentation for their 5.2 FSI V10 engine, as used in the Audi S6 and Audi S8 - the Lamborghini 5.0 V10 has a cylinder bore spacing of 88 millimetres (3.46 in) between centres, whereas the Audi 5.2 V10 cylinder bore spacing is 90 millimetres (3.54 in).[3] The cylinder heads use the four valves per cylinder layout favoured by the Italian firm, rather than the five valve per cylinder variation formerly favoured by the German members of Volkswagen Group - including Audi and Volkswagen Passenger Cars. It was later confirmed by Stefan Reil of Audi's quattro GmbH subsidiary that the new 5.2 litre Lamborghini V10 does share technologes with the Audi 5.2 V10 engine, as is evident by Lamborghini's usage of Audi's Fuel Stratified Injection, and 90 mm cylinder spacing