The Porsche Type 996 is a sports car, and the version of Porsche's "911" Carrera model sold from 1998 (as a 1999 model) through to 2004. It has since been replaced by the Type 997. At its debut, it featured the most significant changes to the Carrera model since its introduction in 1963. Chief among these is the fully water-cooled engine, replacing the previously air-cooled engines used exclusively by the Carrera models. More stringent noise regulations and higher customer expectations for both refinement and performance made the switch necessary. Other significant changes include a sleeker body with a more steeply raked windshield and a re-designed interior. With these differences in mind, many "purists" consider the 996 to be an altogether different car, at least in spirit, than the Carreras that preceded it, as opposed to being a development of the original.
The first 996s were available as a coupes or cabriolets with either rear wheel or all wheel drive and a 3.4 litre normally aspirated engine producing 300 bhp (224 kW). These cars shared the same front end as the 1996 Porsche Boxster. The design for the "fried egg" headlamp could be traced all the way back to the Porsche Panamericana concept car. In 2000, Porsche debuted the 996 Turbo, equipped with four-wheel-drive and a 3.6 litre, twin turbocharged and intercooled flat six producing 415 bhp (309 kW), making the car capable of 3.9 second 0 to 60 mph times. An "X50" upgrade package was available from the factory in 2002, increasing power to 450 hp (336 kW) through minor revisions to the turbochargers and engine control software. Porsche introduced a Turbo "S" in 2004, featuring the X50 engine upgrades and the formerly optional ceramic brakes as standard equipment. In 2002, the standard models underwent minor re-styling, which included switching to the Turbo-style headlamps and to a new front fascia. These were sometimes known as the Mk.II generation of the 996. In addition, engine capacity was also increased to 3.6 litres across the range, yielding gains of 20 horsepower (15 kW) for the non-Turbo models. 2002 also marked the start of production of the 996 based Targa, featuring a sliding glass "green house" roof system like its Type 993 predeccesor.
Like the 993 before it, the 996 platform was used as the basis for two lightweight GT variants called GT2 and GT3. The GT3 was based on the standard RWD 996 Carrera, but was stripped of a great deal of equipment for weight savings, featured stiffer, adjustable suspension and upgraded brakes, and used the bodyshell of the four-wheel-drive version, which incorporated additional front-end stiffening. It was produced in two versions. The first, commonly referred to as the Mk.I GT3, was released in 1999 in all markets, save North America. It featured a naturally aspirated version 3.6L flat six making 360bhp. This engine was shared with the 996 Turbo and was a derivative of the Le Mans winning engine developed for the 911 GT1. The Mk.II GT3 variant was based on the second generation of the 996, and featured updated aerodynamics, and a more powerful version of the 3.6L engine from the MK.I, now producing 380bhp. The Mk.II was the first GT3 marketed in the North America. In 2004 testing of the Mk.II GT3, the car produced 0-60 times of 4.0 seconds, and produced 1.03 g on the skidpad, the second highest number ever recorded by a street legal automobile. Its counterpart, the GT2, was also RWD only, but received an added group of aerodynamic body parts, ceramic brakes of larger diameter, and a re-tuned version of the 996 Turbo's 3.6 litre, twin turbocharged engine featuring larger turbochargers and intercoolers, revised intake and exhuast systems, and re-programmed engine control software. The result was 477 horsepower (356 kW) and 472 ft·lbf (640 Nm) of torque, enough to launch the car from 0 to 60 in 3.6 seconds and to a top speed of 198 miles per hour (316 km/h). Both cars are available only with six-speed transmissions.
The engines in the 1999 and 2000 version have a large failure rate due to a design error. This problem was fixed in mid 2000. One will notice the resale price difference with these model years.
The 99/00/01 cars are all basically the same. 2002 brought a stiffer body which improved safety and handling. They also added seat belt pretensioners. The Tiptronic in 2000 was modified to allow it to enter manual mode by clicking the steering wheel mounted buttons. The Tiptronic would go back to auto mode after 8 seconds. The 2002 cars received the 996 turbo Tiptronic box which is stronger, shifts faster and had 250 shift modes. 2002 cars also received a 3.6L engine which provided an extra 25bhp. It also had some improved parts helping with some reliability issues on the 3.4L engines. The X74 suspension which lowers and stiffens the car was also available as a 2002+ factory modification. Meanwhile, Variocam Plus is standard for every 996's till production has ended.