The W169 is constructed with high-strength steel alloys with bonded joints. Standard equipment included front as well as combined head and thorax-protection side airbags. The front airbags are adaptive with two-stage gas generators operating according to the severity of accident. Optionally rear side airbags (for side-impacts in the backseats) and side-curtain airbags were available.

The force exerted by the seat belt system during a collision adapts dynamically to collision characteristics. The 'active' head restraints (standard for driver and front passenger) reduce neck injury, especially in rear collisions.

The cargo capacity of the W169 was increased by 15 percent over the W168.

Seven four-cylinder engines were available: four petrol (gasoline) (A 150, A 170, A 200, A 200 Turbo) and three diesel (A 160 CDI, A 180 CDI, A 200 CDI) partnered with either five- or six-speed manual gearbox. A continuously variable transmission system called "Autotronic Constantly Variable Transmission" (CVT) is an optional feature.

The petrol A 200 Turbo provides 193 hp (144 kW) and 280 N⋅m (207 lb⋅ft) of torque (rotational force); the diesel A 200 CDI has 140 hp (104 kW) and 300 N⋅m (221 lb⋅ft).

The most powerful engine achieved 0-100 km/h (62 mph) in 8.0 seconds with a top speed of 218 km/h (135 mph). The newly developed direct-injection CDI diesel units use a common-rail direct injection system that improves fuel consumption and reduces exhaust emissions and engine noise.

All the engines meet the tight EU4 emissions limits. A particulate filter system is available as an option for the diesel units to reduce particulate emissions by about 99% without the need for additives.

The A-Class is a front wheel drive car and features traction control (ASR) as standard, as well as electronic stability control and anti-lock brakes (ABS).

Handling is improved by precision tracking and anti-roll support, and by a Parabolic Rear Axle.

A "Selective Damping System", in which the shock absorber forces respond differently according to conditions, is standard. For example, under normal conditions it operates at soft absorption; while cornering at speed it changes to full damping force.

Sales of the W169 were targeted at 50,000 units in 2004. Dr. Joachim Schmidt, Executive Vice President Sales and Marketing, Mercedes Car Group, said that target had been reached even before vehicles arrived in dealer showrooms.[citation needed]

Japan models went on sale in 2005-02-04. Early models include 5-door right drive versions of A 170, A 170 Elegance, A 200 Elegance.[16] 5-door right drive version of A 200 TURBO Elegance was added in 2005-11-10.[17] Due to the body width being larger than 1700 mm, it could not be registered as small car in Japan. (See Vehicle size class#Japan)

Mercedes-Benz A-Class “F-Cell” (2004–)

Mercedes-Benz A-Class F-Cell concept
See also: Mercedes-Benz F-Cell
It is a version of 5-door A-Class hydrogen fuel cell vehicle with 88 PS (65 kW; 87 hp) electric motor. It has a driving range of 160 km (99 mi).[18]

Three A-Class F-Cell cars were used in the 2003 Frankfurt International Motor Show for press shuttle service. On 18 June 2004, 4 production F-Cell vehicles were delivered to Deutsche Telekom and BEWAG/Vattenfall Europe in Berlin.[19]

In 2007, the A-Class F-Cell were delivered to Landsvirkjun and Reykjavik Energy.[20]

A DHL version of F-Cell was unveiled in FC EXPO 2008.[21]

2008 update

Pre-facelift interior
The W169 Model facelift changes included redesigned front and rear fascias and lights, and optional stop-start function on A 150 and 170 models.[22] Active Park Assist enables the car to parallel park itself, with only throttle and brake inputs required from the driver.

The five-door Hatchback and the three-door Coupé vehicles debuted in spring 2008, alongside the refreshed 2009 M-Class and B-Class.[23] Early models include A 160 CDI, A 180 CDI, A 200 CDI, A 150, A 170, A 200, A 200 TURBO.[24]

Japan models went on sale in 2008-08-20. Early models 5-door versions of A 170, A 170 Elegance.[25] Japan models of A 170 was renamed to A 180 in 2009-08-24.[26]