design projects, and instead developed a third option, to tailor the 1.6-liter Type 616 engine to the 902. Before 911 production commenced in 1964, the Porsche Vehicle Research Department had set aside chassis numbers 13328, 13329, 13330, 13352, and 13386 through 13397 for research testing of the 902; research vehicle Serial Number 13394 is the oldest 902 known to exist today. In production form, the Type 912 combined a 911 chassis / bodyshell with the 1.6L, four-cylinder, push-rod Type 616/36 engine, based upon the Type 616/16 engine used in the Type 356SC of 1964–1965. With a lower compression ratio and new Solex carburetors, the Type 616/36 engine produced five less horsepower than the 616/16, but delivered about the same maximum torque at 3,500 rpm versus 4,200 rpm for the 616/16. Compared to the 911, the resulting production Type 912 vehicle demonstrated superior weight distribution, handling, and range. To bring 912 pricing close to the 356, Porsche also removed some features standard on the 911. As production of the 356 concluded in 1965, on April 5, 1965, Porsche officially began production of the 912 coupé. Styling, performance, quality construction, reliability, and price made the 912 a very attractive buy to both new and old customers, and it substantially outsold the 911 during the first few years of production. Porsche produced nearly 30,000 912 coupé units and about 2500 912 Targa body style units (Porsche's patented variation of a cabriolet) during a five-year manufacturing run. Production of the Targa, complete with removable roof and heavy transparent plastic rear windows openable with a zipper (later called 'Version I' by Porsche and the 'soft-window Targa' by enthusiasts), commenced in December 1966 as a 1967 model. In January 1968, Porsche also made available a Targa 'Version II' option ('hard window Targa') with fixed glass rear window, transforming the Targa into a coupé with removable roof. The 912 was also made in a special version for the German autobahn police (Polizei) and for the Dutch police (Rijkspolitie); the 100,000th Porsche car was a 912 Targa for the police of Baden-Württemberg, the home state of Porsche. In the April 1967 edition, the Porsche factory's Christophorus Magazine noted: "On 21 December 1966, Porsche celebrated a particularly proud anniversary. The 100,000th Porsche, a 912 Targa outfitted for the police, was delivered." Porsche executives decided that after the 1969 model year, continuation of 912 production would not be viable, due