The second generation of the Subaru Impreza compact car was introduced in 2000 and manufactured up to 2007 by Subaru in Ōta, Gunma, Japan, in both sedan (GD series) and five-door Hatchback (GG series) bodystyles, as well as two intermediate facelifts throughout its lifespan.

The Impreza received naturally aspirated 1.5, 1.6, 2.0, or 2.5 liter flat-four engines, with the performance oriented WRX and WRX STI models upgraded to turbocharged versions of the two latter options. Export models typically received all-wheel drive, with front-wheel drive also available in the Japanese domestic market.

History

Pre-facelift (“Bug-eye”): 2000–2002 Built on a significantly modified version of the first generation platform, the new Impreza followed much the same formula as its predecessor, including a similarly contoured silhouette. Despite this, the front-end styling—distinguished by ovoid headlamps—attracted significant controversy. This version of the Impreza has gained the nickname 'Bug Eye' among Subaru enthusiasts. Body dimensions for the sedan increased by in length, in width, and in height; wheelbase increased by . To satisfy Japanese vehicle size tax regulations, the width of the hatchback increased by just to and therefore remaining in the limit "5" classification. As Subaru had intended to homologate the sedan chassis for rallying, the decision to increase the width of the sedan—which placed it into the higher taxed number "3" division—brought added stability. Likewise, the increase in track for the sedan also worked to aid handling, with the hatchback gaining just . Other main improvements to the chassis included a 120 percent increase in torsional rigidity; mainly due to revisions in front subframe design. The suspension retained its basic MacPherson strut in the front and rear, although Subaru altered the geometry.

The GD chassis gains nearly in weight over the GC chassis. Subaru claims that compared to the previous model, the GD chassis is 148 percent and 82 percent stiffer in torsional and beam rigidity, respectively. This stiffness is primarily due to the addition of a steel "ring" which encircles the cabin at the B-pillar. While the stiffness was increased for passenger safety, it has the added benefit of providing more stability for motorsports events. Firehouse magazine notes that the Jaws of Life need to cut the Subaru's B-pillars at certain points in order to cut through the car frame. In terms of safety, the GD chassis scored much higher than the GC chassis and earned a "Good" rating (highest mark) from the IIHS's offset crash test. 4 stars front driver, 5-star front passenger and 4-star side safety ratings from the NHTSA.

In Subaru's home market of Japan, the Impreza range started with the 1.5i—powered by the 1.5-liter EJ15 SOHC engine and paired with a manual transmission or optional automatic. Subaru fitted a DOHC version of the same engine to the automatic-only 1.5R, which also featured an active valve control system. For both models, front- and all-wheel drive versions were available. Starting from 2006, Subaru phased out the EJ15 engine in favour of the new EL15.

In Greece a turbocharged version of the 1.6 liter version was also offered. In addition to the turbo, it received new mapping, new fuel injectors, new pistons, a dual exhaust, and a mid-sized spoiler. This engine makes .

Subaru released this generation of Impreza to North America in 2001 for the 2002 model year. The release of the 2.0-liter turbocharged Impreza WRX, did not occur until the 2002 model year, and the Impreza WRX STI was delayed until the 2004 model year. The US version of the STI includes various departures from the Japanese and European counterparts, such as a turbocharged 2.5-liter EJ257 engine, rather than the twin scroll turbo 2.0 L engine sold elsewhere. All 2006 American Imprezas use some form of the 2.5-liter EJ25 engine since naturally aspirated and turbocharged are available.

The Outback Sport was sold in Australia for model years 2001–2007, but it was renamed as the Impreza RV with the same color scheme as the American version. The Australian version had a dual-range manual transmission, not available in the United States. The Impreza was Wheels magazine's Car of the Year for 2000.

First facelift (“Blob-eye”): 2002–2005 After mixed reaction to the round headlight design, in 2001 Subaru enlisted the help of Peter Stevens of Prodrive, who updated the car's fascia in 2002 (2003 in the US for the 2004 model year), with more rectangular headlamps. For the US market, the facelifted Impreza was offered as 2.5 RS Sedan and TS Wagon, 2.5 Outback Sport Wagon, WRX Sedan and Wagon, and the new WRX STI Sedan. Sport Package was optional for the RS, and the WRX could be ordered with Premium Package. The RS, TS, Outback Sport, and WRX are available with manual or automatic transmission, while the sole transmission for the STI is 6-speed manual. After this facelift, a sedan without the wide fenders was offered for the Japanese market. This version of the Impreza has gained the nickname 'Blob Eye' among Subaru enthusiasts.

In 2005, Subaru made their AVCS standard on all engines used in the Impreza.

Second facelift (“Hawk-eye”): 2005–2007 From June 2005 in Japan (2006 model year) Imprezas have been redesigned, along with new headlights, taillights, and bumpers. Greek designer Andreas Zapatinas, formerly of Alfa Romeo, penned the updated front-end in 2004. The facelift introduced Subaru's new corporate face, including its controversial "jet intake and wings" grille design that first appeared on the Subaru R2 kei car. The new corporate face was designed to pay homage to their aircraft manufacturing roots, the Nakajima Aircraft Company. This version of the Impreza has gained the nickname 'Hawk Eye' among Subaru enthusiasts.

Safety

WRX

In December 2000, Subaru updated the WRX to the second generation. The GDA WRX model also retained the 5-speed manual transmission gearbox design from the GC8. Subaru later released a new 6-speed gearbox for the STi model GDB that is significantly stronger.

The GD chassis, along with the WRX and STI, underwent two styling changes in its life cycle. The original styling applied to A and B. Initially this design proved to be rather unpopular which prompted a more conventional design for the applied C, D and E models. The second facelift applied to the F and G versions.

The WRX STi gained alloy wheels over the previous wheels, and the 5-speed manual transmission (reputed to be one of the car's weak points) was changed to an STi-engineered 6 speed manual transmission. The engine, retained from the Version 6 STi, still retains the semi-closed deck block and is still labelled as the EJ207. However the engines did gain AVCS, further improving their low-end torque production. The interior was updated with an STi logo on the gauge and the tachometer also has a red shift light. Brembo 4 piston front and 2 piston rear brakes came standard on the STi and were an option on the bare-bones Type RA STi, which still carried the Subaru 4 piston front/2 piston rear brakes as standard. Externally, the STi has a larger hood scoop and has foglight covers with the STi logo embossed on them. The DCCD was updated to work with anti-lock brakes. During braking, when the ABS is on, the DCCD will set itself to open-mode (no locking).

The version nomenclature was dropped from the name. Japanese and other auto-enthusiasts often refer to the chassis as GDB/GDF (the STi has a 'B' or 'F' (for USDM models) whereas the regular WRX had an 'A'). The fourth character of the VIN gives the revision (A to F where G is the 2007 version).

In 2000, most of Asia, Oceania and Europe received the new STi. The engine was detuned to meet emission standards. Engine output was variously rated from at 6,000 rpm and of torque at 4,000 rpm, to at 6,400 rpm and of torque at 4,000 rpm depending on the market.

2005 STis received the long-awaited DCCD control available in other markets, as well as a slight wheelbase increase to match the Japanese-spec WRX STi Spec-C and has .

Japan

Applied A (2000) August 2000 brings the 2001 WRX NB sedan. It is powered by an EJ205 with AVCS coupled with an IHI TD04-HL turbocharger. The engine produces at 6,000 rpm with 35 kg·m (246 ft·lbf, 333 N·m) at 3,600 rpm. The wheels are in diameter. The car uses 2 pot/1 pot front and rear brakes. The front brake rotors are ventilated while there are rear solid disks. It has a Torsen rear LSD and a 4.44 final drive ratio. The transmission has close-ratio gears unique to Subaru of Japan at that point in time. The car has a curb weight of .

Aside from the WRX Type RA STi, the Sports Wagon STi also returned from the previous model, although it retained the 4 pot/2 pot Subaru calipers from the preceding STi while using narrower 17" wheels from the Legacy. Similar to the GDB, The foglight covers featured a white STi logo on them. The WRX Type RA STi was used for Group N homologation.

Applied B (2001) The 2002MY WRX NB sedan debuts in September 2001. The mechanical specifications are similar to the previous year's model but the curb weight has been increased to .

Along with the rest of the Impreza line, the grille and body of the WRX STi was lightly updated by Peter Stevens to give it a more angular look when seen from the side. The color of the STi logo on the foglights was changed to pink. Aside from minor suspension improvements and a small increase in torque output, virtually everything remained unchanged.

The Type RA was replaced by the WRX STi Spec C. This model was much lighter than the Type RA as it received lighter glass and body panels. The Spec C's handling was much improved due to an increase in caster (from 3.5 degrees to 5 degrees). This was achieved not by changing the suspension mounting point, but by lengthening the wheelbase by . This was done by including different control arms. This increased caster significantly helped the turn-in capabilities of the car. The Spec C also has a steering rack ratio of 13:1. The transmission is supplied with its own oil cooler.

The Sports Wagon STi had ceased production by this time.

Applied C (2002) The WRX NB-R sedan is released in November 2002. The power and torque ratings are the same as the previous year. The wheel diameters are increased to 17" in size. The rear brake rotor is changed to a ventilated disk, leaving the car to use only ventilated disks for braking. The car has 4 pot/2 pot front and rear brakes. The rear wing is on wing risers. The car now weighs .

The WRX STi was used for Group N homologation.

Applied D (2003) The WRX line receives a body exterior update and an improved transmission. The WRX STi is now capable of being ordered with DCCD.

The WRX STi Spec C Type RA was released. It sported a carbon-fiber wing and a carbon fiber lip. It also had a new set of BBS wheels as well as a newly tuned engine.

The WRX STi V-Limited was released. It sports 4-way dampers tuned by Subaru World Rally Team's Group N driver Toshi Arai. The WRX STi was used for Group N homologation.

Applied E (2004) The WRX WR-limited is introduced. The car receives an STI spoiler and an STI front chin. There is a WR-stickered titanium shift knob. The wheels are changed for STI, gold-colored Rays-sourced wheels.

This was the first Impreza STi model to be offered in the United States. Subaru unveiled this model at the Detroit International Auto Show, only 1 month after Mitsubishi announced the arrival of the 271 horsepower Lancer Evolution 8, which out-performed the 2.0L WRX.

Applied F (2005) The WRX has an option to receive the same spoiler as the WRX STI. The WRX has a viscous rear LSD now.