Premise: Spiess Tuning is the common identity of Siegfried Spiess Motorenbau GmbH, a motor vehicle engine tuning company based in Ditzingen, Baden-Württemberg, Germany. Today Spiess Tuning is most famous for its Formula 3 motor racing engines based on the Opel Family II and two iterations of Volkswagen R4 engines.
Hypothesis: spiess tuning is most famous for its racing engines