The new 325 and 330 engines feature:

• Fully electronic throttle (drive-by-wire), replacing the previous electromechanical system. 
• Revised valve timing and lift contribute to increased power. 
• Redesigned dual resonance intake system. 
• Aluminum cylinder block and head.
• Steplessly variable intake and exhaust valve timing.
• Electronically controlled engine cooling.
• Ultra Low Emissions Vehicle (ULEV) compliance.

Compared to previous 323 models' 2.5-liter engine, the new 325 engine remains at 2.5 liters but delivers 184 hp and 0-60 mph in 7.1 seconds with the manual transmission  and 8.1 seconds with the automatic transmission. US EPA mileage of 20 mpg city and 29 mpg highway.

Compared to the previous 328 models' 2.8-liter engine, the new 330 engine is enlarged to 3.0 liters and delivers 225 hp, 214 lb-ft. of torque, and 0-60 mph in 6.4 seconds with the manual transmission, and 7.0 seconds with the automatic transmission. US EPA mileage of 21 mpg city and 30 mpg highway. 

All 3 Series models feature a choice of transmissions:

• The standard 5-speed manual or 
• The optional 5-speed STEPTRONIC automatic transmission.

Both the manual and the automatic transmissions have lifetime transmission fluid, requiring no regular maintenance.

The manual transmission features a self-adjusting clutch for longer clutch life.

The five-speed STEPTRONIC automatic transmission has three settings; automatic, manual and sport. This provides the option of manually shifting for performance or control, automatically shifting in commute traffic, and adding low end torque when needed. 

The fully independent suspension system includes:

• Strut-type front suspension with aluminum lower arms, optimized geometry and hydraulic cushions.
• Multi-link rear suspension with aluminum transverse links.
• Hydraulic mount for the differential.
  

Ergonomic and convenience features include:

• Powerful 4-headlight system is standard, and Xenon low beams are optional.
• Standard multi-function remote control, integrated into the head of the master key, operates many electrical functions including
  2-step unlocking, remote trunk release, opening of power windows, 
  available moonroof (sedan, sport wagon, coupe), power top (convertible) and switch-on of interior lights.
• Vehicle and Key Memory allows users to personalize many electronic comfort, convenience and security features.
• Leather-covered tilt/telescopic steering wheel is standard with fingertip multi-function controls standard in all models except the 325i/xi.
• Single-wipe function windshield wipers with adjustable and vehicle-speed-sensitive wiping intervals.
• Ambiance Lighting has LED lights in the roof to illuminate the console area in soft orange light, helping occupants find controls at night.
• 6-way manual front seats standard in sedans, sport wagon and 325Ci coupe; 6-way power in 330Ci coupe; 8-way power in convertibles; 6-way power sport seats available in sedans, sport wagon, 325Ci coupe
• All Sport Packages include sport front seats with thigh-support adjustment; power if combined with Premium Package or stand-alone power-seats option.
• All models with power front seats include driver's-seat and outside-mirror memory system with 3 positions, automatic tilt-down of right outside mirror for backing up, interior trim panels in color-keyed, aluminum-finish or Myrtle wood depending on model, color and equipment.
• Standard 10-speaker audio system with optional Harman Kardon audio system. The speaker configurations are specific to each body type.
• 1-touch operation of all side windows.
  

Safety features include:

• Body structure engineered for excellent occupant protection in full and offset frontal impacts, side impacts and rear impacts.
• Optimized safety design of steering column.
• Front-seat safety belts with automatic tensioners and force limiters.
• Front-seat side-impact airbags standard.
• Differentiated deployment system manages deployment of front-impact airbags and front safety-belt tensioners.
• Automatically unlocks doors, turns on interior lights and 4-way hazard flashers after accident impact.
• Front-seat Head Protection System (HPS) is standard in sedan and coupe models.
• Battery Safety Terminal is standard. After a severe impact, the high-current connection between the battery and the starter cable is automatically severed to help prevent a possible short circuit.

The BMW Full Maintenance Program for 3 years or 36,000 miles is included in the base price.