The 159 placed third in the 2006 European Car of the Year awards. Production of the 159 ended in November 2011, and around 240,000 cars were built. The 159's late transition to what was fundamentally made as an E segment platform resulted in the 159 having excessive weight, a problem shared by the Brera coupé and Spider.
In 2008, changes made to the interior, dashboard, instrumentation with aluminium components introduced for various parts of the car, which reduced kerb weight by 45 kg (99 lb). Due to its executive car platform, the 159 is 225 mm (8.9 in) longer, 85 mm (3.3 in) wider than its predecessor.
However, the considerable growth in dimensions deterred many 156 owners from considering the 159 as a direct replacement model. Due to the sophisticated Premium platform that the 159 is based upon, high level of passive safety was achieved, and the torsional rigidity of the chassis is one of the best in this category at 180.000 daNm/rad.
The 159 was designed by Giorgetto Giugiaro in collaboration with the Centro Stile Alfa Romeo. The nose features a traditional Alfa Romeo V shaped grille and bonnet, and cylindrical head light clusters. Similar to its coupé counterpart, the front of the car was influenced by the 2002 Brera Concept also designed by Giugiaro.
A high waistline broadens until it reaches the rear "C" pillar. Several exterior design cues were intended to make the car appear larger, supposedly to appeal to potential buyers in the United States; however, the 159 was never exported to that region.
The interior also features styling treatments familiar from earlier cars, including the 156, such as deeply recessed instruments which are angled towards the driver. Alfa Romeo intended for the 159 to compete more directly with BMW, Mercedes-Benz and Audi by using higher quality interior materials.
Model year changes
Several levels of trim were available depending on the market. Four trim levels namely Progression, Distinctive, Exclusive and Turismo Internazionale (TI) were generally available. In the United Kingdom, there were three available levels of trim: Turismo, Lusso and Turismo Internazionale (TI). Among other options, the 159 was also available with the Blue&Meinfotainment system.
A Sportwagon variant was introduced at the Geneva Motor Show in March 2006. An automatic gearbox option for the 2.4 JTDM diesel model was also launched that year, and later extended to other versions. In 2007, a four wheel drive diesel model was introduced, and the 2.4 litre diesel engines' power output was increased to 210 PS (154 kW; 207 hp), with a newly reintroduced TI trim level also available as an option.
For the 2008 model year, the mechanics and interiors of the 159 were further developed. A 3.2 litre V6 model was offered in front wheel drive configuration, achieving a top speed of 250 km/h (155 mph). All model variants were now equipped with Alfa Romeo's electronic "Q2" limited slip differential. As a result of newly introduced aluminium components, a 45 kilograms (99 lb) weight reduction was achieved. The revised 159 range was introduced at the Geneva Motor Show in March 2008.
For the 2009 model year, Alfa Romeo introduced a new turbocharged petrol engine variant badge as "TBi", this 1,742 cc unit has direct injection and variable valve timing in both inlet and exhaust cams. This new engine is rated at 200 PS (147 kW; 197 hp) and 320 N⋅m (236 lbf⋅ft) of torque. Eventually this unit would replace the GM derived 2.2 and 1.9 JTS units. Also in the same year, a new 170 PS (125 kW; 168 hp) JTDm diesel engine became available.
The 159 was discontinued in the United Kingdom on 8 July 2011.
The 159 was available in both front and four-wheel drive configurations. The "Q4" four wheel drive system utilises a Torsen type C twin differential (front and centre differential in the same unit with an open front differential) and was available on the 3.2 litre petrol and 2.4 litre diesel engines.
The gearbox is a six speed manual on most models (with the 1.8 litre model having a five speed manual), and a six speed automatic Q-Tronic gearbox (Aisin AW TF-80SC) was available for the 1.9 diesel, 2.4 diesel and 3.2 petrol models. The Selespeed semi-automatic gearbox was available in some markets with the 2.2 petrol engine.
The 159 is fitted with seven airbags as standard, with additional knee airbags also available as an option. The car performed well in rear end crash protection tests, benefiting from "anti whiplash" seats.
The 159 passed the Euro NCAP car safety tests with following ratings:
A car strongly resembling a 159 can be seen in multiple episodes of Psycho Pass.
The 159 contested the Bathurst 12 Hour race for production cars in 2007,2009 and 2010. Competing with the 2.4 Litre JTDM diesel engine, it won the Alternative Energy Class in each of these three races.