The first generation of the Zafira is usually referred to as Zafira A, as is customary for Opel models. Developed with the aid of Porsche, the Zafira was first shown in concept form at the 1997 Frankfurt Auto Show and entered series production in January 1999, with sales beginning in April. The car was based on the same platform as the 1998 Astra G and shared much in common with that car. The Zafira A body was used in GM/Opel's concepthydrogen-powered fuel cell vehicle the HydroGen3. Offered with a series of petrol engines and initially a single diesel offering, the "X" engines were replaced by the newer "Z" engine generation in 2000. These featured variable intake manifoldsand were able to meet Euro 3 emissions standards. The Opel Zafira has seven seats arranged in three rows, the back row of which can be folded into the floor to create more space, individually or together, rather than requiring that the extra seats be physically removed from the vehicle. The system was named Flex 7. In TüV's ranking of the quality of three-year-old cars, the Zafira was by far the best Opel, only slightly behind the winning Ford Focus. Introduced at Geneva in February 2001, the turbocharged Zafira OPC went on sale in October of the same year. With 192 PS (141 kW), this was the fastest minivan on sale in Europe. Only available with a five-speed manual transmission, 0–100 km/h (62 mph) can be reached in 8.2 seconds and the top speed is 220 km/h (137 mph). The popular 2-litre turbodiesels were complemented by a 125 PS (92 kW) 2.2 litre option in January 2002.