On May 23, 2003, Fuji Heavy Industries continued to offer the "Blitzen" model in Japan only, and debuted the fourth generation Legacy B4 sedan for the Japanese domestic market with the slogan "Blood type: B4" and advertisements featuring a remixed version of "Gymnopédie No.

The Legacy B4 sedan and station wagon was voted the 2003–2004 Japan Car of the Year, Subaru's first win for the award after fighting off stiff competition from Toyota Prius and Mazda RX-8.

The Japanese Legacy received a cosmetic update in May 2006. Notable changes included new bumpers, headlights, front fenders, grille, and rear combination lamps.

Kazuyoshi Miura was used as a spokesman for the Hardtop, Touring Wagon and Outback and the commercial song were from Japanese rock band L'Arc-en-Ciel.

[2] It consists of 2 CCD cameras with one on each side of the rear-view mirror, that use human-like stereoscopic vision to judge distances and generally keep tabs on the driver.

It includes a 2.5L twin scroll turbocharged engine rated at 285 PS (210 kW; 281 hp) at 5,600 rpm and 392 N⋅m (289 lb⋅ft) of torque at 2,000–4,800 rpm, as well as Bilstein shocks, 18x8-inch BBS forged wheels (from S203, S204) with Bridgestone Potenza RE050A 235/40R18 91W tires, Brembo 6-piston front and 2-piston rear brake calipers (from Subaru Impreza type RA-R) and Vehicle Dynamic Control stability control.

[5][6] Subaru of America commenced production of the Legacy BL and BP in January 2004 for the United States and Canadian markets.

Lance Armstrong was used as a spokesman for both the sedan and station wagon, and Sheryl Crow sang her 1996 hit "Everyday Is a Winding Road" in USA market commercials.

The Lafayette Factory-built Subaru Legacy won 2005 International Car of the Year for Most Dependable/Sedan from Road & Travel Magazine, 2005 Automobile All-Stars for All-Star Family Car from Automobile Magazine and The 2006 International Engine of the Year Award in the 2.0 liter to 2.5 liter category for EJ255 engine.

The model marked the return of a turbocharged engine to the North American Legacy, featuring a new turbocharger from IHI coded the VF40, a single scroll turbo which was replaced in 2007 with a VF46 turbo which was slightly better flow with less turbo spool time, and the EJ255 (Years 2005 to 2006 used the EJ257 including the EJ257 heads but kept the EJ255 code) rated at 250 hp (186 kW), a 2.5-liter unit derived from that of the USDM Impreza WRX with 20 hp (15 kW) more.

[clarification needed] Due to advancements in turbocharger technology and tightening emission standards, the twin-turbo setup was not used.

Turbocharged models, along with the H6 engine, offered Subaru's first 5-speed automatic transmission, featuring SportShift technology licensed from Prodrive, Ltd.

For the 2008 model year, the Legacy sedan received facelift with new bumpers, front fenders, tail lights, and alloy wheels.

For 2008, the 2.5i USA model has been certified PZEV emissions, and a badge has been attached to the rear of the vehicle on the bottom right hand side of the trunklid or tailgate.

The Ecomatic Autogas Hybrid is a version of the Legacy with the 2.0R or 2.5i engine that can run on LPG for the German market.

The 2008 model was limited to 250 units, and has black Brembo brakes and slightly different Enkei rims.

It included Bilstein shocks, a rear suspension kit with partial ball-bearing-jointed bushings, 5 mm (0.2 in) lower springs, Brembo brakes (4-piston front, 2-piston rear) with stainless steel mesh-type brake hose, 18-inch Enkei wheels 2.5 kg (5.5 lb) lighter than stock, front and rear STI spoilers, leather and Alcantara front seats, and an 8-way power driver seat with memory settings.

The bonnet, fifth door, steering column and some parts are made of aluminum to reduce weight.