GRS191 / UZS190 (2005)
In September 2005, the GS 350 (GRS191) and GS 430 (UZS190) went on sale in Japan; the GS 350 using a 3.5-liter 2GR-FSE V6 engine with D4-S direct injection, while the GS 430 used the same 4.3-liter 3UZ-FE V8 used in the previous model. Sales in the United States began in March 2005 for the 2006 model year, with the initial U.S. model lineup including the GS 300 (GRS190), featuring a ULEV certified 3.0-liter 3GR-FSE V6 engine, and the GS 430. The GS 300 featured a D4 direct-injection fuel system for all markets except Continental Asia, excluding Singapore, becoming Toyota's first vehicle equipped with direct injection sold in the United States. The 3.0-liter engine was also found in the Toyota Mark X as well as the Zero Toyota Crown, however the new GS 300 was never offered in the Japanese market. The GS 300, GS 350, and GS 430 engine options were paired to a new 6-speed automatic sequential shift gearbox. An all-wheel drive system was made available in the GS 300, thus becoming the first Lexus sedan to offer such a configuration;[17] the system varied the front/rear wheel torque split anywhere from 50/50 to 30/70 depending on conditions.
Also new to the GS line was an Electric Power Steering (EPS) system replacing the previous model's hydraulic steering pump, while the V8 model featured a Variable Gear Ratio Steering (VGRS) system and Electronically Controlled Brake (ECB) a type of brake-by-wire system.[17] In August 2005, the GS 430 was the first car by Toyota with Adaptive Variable Suspension (AVS).[18] AVS monitors and adjusts the shock-absorber settings at each wheel, depending on the conditions. On rough roads, for example, damping is reduced for a more comfortable ride. And, while cornering, the suspension is tightened to help reduce body lean and provide even greater responsiveness.[19] Using the EPS system the GS can automatically compensate for crosswinds.[20]
For the 2007 model year, the GS 350 replaced the GS 300 in the U.S. and other export markets. Due to a change in SAE testing procedures, the 2007 GS 430 horsepower rating was reduced from 300 to 290 (with 319 lb·ft. of torque), while the V6-powered GS 350 was rated at 303 hp (with 274 lb·ft. of torque). Lexus reported 0-60 times of 5.7 seconds for both vehicles.[21] For 2008, the GS 350 came with Vehicle Dynamics Integrated Management (VDIM), which was previously standard only on V8 and hybrid models. The Adaptive Variable Suspension (AVS) was now an option on the V6 model as well.
In 2007, Consumer Reports predicted reliability survey blamed the 2006 first-year GS in the all-wheel-drive form, which had problems in integrity (rattles), body hardware and sound system, as the sole reason for lowering Lexus' overall score.[22] Despite the reliability issues among 2006 GS models, the vehicle earned a "Recommended" rating from Consumer Reports for vehicle features, overall value and previously automatically assumed reliability for that year. However, the problems have apparently been solved, and the GS AWD was rated "average" in later years.
GWS191 (2007)
Unveiled at the 2005 New York International Auto Show, the hybrid GS 450h (GWS191) joined the GS line in 2006 for the 2007 model year. It was the first mass-production rear-wheel drive luxury hybrid car. Its powertrain included a naturally aspirated 3.5-liter 2GR-FSE V6 engine mated to an electric motor and a continuously variable transmission. This powertrain made use of the Lexus Hybrid Drive system of integrating electric and gasoline engine motors, giving the GS 450h a Super Ultra Low Emissions Vehicle (SULEV) emissions rating.[23] In some markets, however, the car could only be purchased with at least one option package, which raises the price by several thousand dollars. The rear-mounted battery also consumed significant trunk space, which was improved in 2009 when Lexus redesigned the trunk area to increase space by forty percent,[24] from 7.5 cuft[25] in 2007 and 2008, to 10.6 cuft.[24] The GS 450h went on sale in Japan on 16 March 2006.
URS191 (2008)
A 4.6-liter GS 460 (URS191) replaced the GS 430 in 2007 for the 2008 model year. Equipped with the new 4.6 liter 1UR-FE/1UR-FSE V8 engine generating 342 hp (with 339 lb·ft. of torque) and an 8-speed automatic transmission. Lexus reported a 0-60 time of 5.4 seconds for the GS 460.[27] Along with the hybrid GS 450h and previous GS 430 models, the V8-powered GS 460 offered the Active Stabilizer Suspension System for improved handling.
Coinciding with the introduction of the GS 460, the GS lineup received a mid-cycle styling refresh, including a revised front bumper, headlights and grille, turn signals added to the side mirrors, and new wheel options and exterior colors. Inside the vehicle, the GS received a redesigned steering wheel, revised instrument cluster gauges, and different trim pieces.
