From 1999, there were three different models of the 996: a base, or Biposto; the 996S with Öhlins suspension; the 996SPS (Europe only) which had a more powerful engine and less weight thanks to some titanium and carbon fibre parts. From 2001 the 996R replaced the 996SPS and featured the new 998 cc (60.9 cu in) Testastretta engine. There was also the 748, which offered less horsepower.
The 996 had larger 98 mm (3.9 in) pistons, larger valves, a stronger crankshaft and crankcases ported from the 916 SPS. But since the 916 camshaft gave a softer, less peaky power delivery and less top-end power (83.5 kW (112.0 hp) versus the SPS’s 92.4 kW (123.9 hp)) the 996 was built with a new air intake system with two fuel injectors per cylinder. A new airbox and a distinctive underseat exhaust system were also built into the new design. The chassis was also modified. Lighter wheels were introduced along with improved calipers, discs and pads stronger compared to the 916. The suspension system was still the same Showa design but both the front and back were fully adjustable for damping and preload.