Badged as a 95, Saab consistently advertises it as the 9-5. The name is pronounced "nine five" rather than "ninety five". This model should not be confused with the Saab 95, produced from 1959 to 1978.
The 9-5 is powered by Saab's B205 and B235 straight-4 engines, and in Europe by Alfa Romeo's 1.9 JTD 16V diesel straight-4. A version of the GM 54° V6 powered by a unique asymmetrical low-pressure turbocharger was available from 1999 to 2003. This engine was available only with an automatic transmission, and cars with this engine installed are distinguishable by their twin tailpipes. It was only available on Arc, SE, and Griffin models. In 2004, the V6 engine was replaced by a high pressure turbo straight-4 engine producing 220hp (160kW). By 2008 this engine was producing 260hp (190kW) even in the non-Aero model (US model).
The B235-based 9-5 models have suffered an abnormally high rate of engine failures due to engine oil sludge. This primarily affected the 1999-2002 models. Saab refined the engine's positive crankcase ventilation system (PCV) for the 2003 and later model years, virtually eliminating the problem. Additionally, SAAB created update kits to retrofit to the 1999-2002 cars since they cannot be easily modified to accept the 2003 and later system. Mounting complaints by 9-5 owners forced GM to offer an 8 year warranty on the engine in 4 cylinder models, provided the owner can produce proof that they followed the manufacturer's oil change intervals. Saab now also recommend the use of fully synthetic oil as a preventative measure.
The 9-5 was available with an Aisin Warner 4-speed automatic transmission from 1997-2001. A new Aisin Warner unit replaced the dated 4-speed automatic with a 5-speed automatic. A 5-speed manual transmission is fitted as standard to the base models and the Aero.
In 2005, an updated version of the 2.0L turbocharged I4 was introduced in the European market together with the 2006 9-5. The engine is sold as 2.0t BioPower, and it is optimized to run on E85 producing 132kW (180hp) at 5500rpm. There is also a 2.3t BioPower version sold from 2007.