Porsche introduced a Turbocharged 924 to increase performance, but there were engine cooling issues and the price was considered high for the time, which hampered sales. Rather than scrap the design entirely and engineer a fresh replacement, Porsche's executives decided to take an evolutionary standpoint on development of the 924, much as they had with generations of the 911. Although model numbers would change, the 924 would provide the core basis for its replacement, the new model would be an evolution of the old. Using the 924 as a starting point, Porsche thoroughly re-worked the platform and scrapped the Volkswagen engine, installing in its place a new 2.5 litre straight-4 engine based on the 928's 5.0 litre V8, although very few parts were actually interchangeable. The engine was factory-rated at 144 bhp in its U.S. configuration. Revised bodywork, similar to that of the 924 Turbo and 924 Carrera GT, a fresh interior and upgrades to the braking and suspension systems rounded out the major changes.
Porsche introduced the 944 for MY 1982 to great anticipation. In addition to being faster, the 944 was more equipped and more refined than the 924, it had better handling and stopping power and was more comfortable to drive. The factory claimed 0-60 mph time of over 9 seconds was actually rather modest, and seems to presume full clutch engagement at low rpm (i.e. minimal clutch slipping and no wheelspin). In fact a more dramatic acceleration would result from a high-rpm clutch-drop, and the car is more than capable of "burning rubber." The factory claimed top speed of 130 mph, was also pessimistic Autocar having verified a top speed of 137mph.
In mid-1985 the 944 underwent its first significant changes. A new dash and new door panels, an embedded radio antenna, an upgraded alternator (from a 90 amp to a 115 amp), increased oil sump capacity, new front and rear cast aluminum control arms and semi-trailing arms, a larger fuel tank, optional heated and powered seats, a Porsche HiFi sound system, and revisions in the mounting of the transaxle to reduce noise and vibration all debuted. The "cookie cutter" style wheels used in the early 944s were upgraded to new "phone dial" style wheels. 1985 model year cars incorporating these changes are sometimes referred to as "1985B" or "1985 1/2" cars.
In early 1990, Porsche engineers began working on what they had intended to be the third evolution of the 944, the S3. Once invested into the development process, they realized that so many parts were being changed that they had produced an almost entirely new vehicle. Porsche consequently shifted development from the 944 S3 to the car that would replace the 944 entirely, the 968. The 944's final year of production was 1991; in 1992 the 968 debuted. The 968 was sold alongside the 928 through 1995, when both models were discontinued.Source: Wikipedia.