2011–2015
In early 2007, development began on the L10 series GS[43][44] under Yoshihiko Kanamori, with the design process finalizing under new president and CEO Akio Toyoda's direction in 2009. Design patents were filed in Japan on 6 October 2010 for the production model and a conceptual variant on 29 March 2011. In April 2011, Lexus showed the LF-Gh concept (Lexus Future Grand-Touring Hybrid) at that year's New York International Auto Show, previewing the stylistic direction of future Lexus models. The LF-Gh featured a large, spindle-shaped front grille, and press information further indicated that it had a new interior design which included an analog clock.[45] The LF-Gh concept vehicle was taken by automotive journalists as an indication of what the fourth generation Lexus GS would look like.[46]
The fourth generation GS had its world premiere at the Pebble Beach Concours d'Elegance in California in August 2011. The vehicle was shown to have a more subtle version of the LF-Gh's spindle grille, while overall exterior dimensions are almost identical to the previous generation.[47] L-shaped LED front daytime running lamps and rear LED tube lamps are a new design feature.[47] The fourth generation GS was the centerpiece of Toyota chairman Akio Toyoda's initiative to restore passion to the Lexus brand and better compete with German luxury automakers that had been gaining market share in the United States. It was reported that Toyoda initially opposed the styling choices made for the new model, but later thanked the design team that persuaded him to greenlight the project.[48] Unlike the first three generations, the fourth generation GS is not based on any Crown models as it is built on a separate New N platform.[42]
At its debut, the fourth generation model was shown in rear-wheel drive GS 350 (GRL10) form, powered by a V6 engine linked with a six-speed automatic transmission.[47] Three driving modes are featured, ranging from fuel-conserving Eco to Sport S and Sport S+ which facilitate more sporty transmission shifting and engine throttle settings, as well as suspension damper and steering adjustments.[47] The chassis has been redesigned, and overall curb weight is reduced.[47] To reduce unsprung mass the new GS utilizes aluminum for all its suspension components.[49] The GS 350 F Sport adds a rear-wheel steering system for improved handling on rear wheel drive models. New larger 14-inch brakes come standard as well as 19-inch F Sport wheels, a new front bumper, rear spoiler, F Sport steering wheel, F Sport seats and a new suspension system with AVS adjustable dampers.
The redesigned interior gains the Lexus Remote Touch mouse controller system in place of the previous touchscreen, linked to a split-view 12.3 in widescreen dashboard display.[47]
It also features a new technology, Save energy + airflow control (S-FLOW), which is the world's first system that sends air only to where vehicle occupants are seated in order to maintain and improve comfort while also improving fuel efficiency.[50]
Other interior features include Mark Levinson surround sound system.[47] Front 18-way power seats are available; 10-way power seats are equipped standard. Optional features further include a pre-collision system, Heads-Up Display, blind spot monitor, lane keep assist, and Driver Monitoring System.[47]
Variants such as the GS 350 and GS 250, as well as their F Sport variants, began sales in Japan on 26 January 2012, followed by the GS 450h and the GS 450h F Sport on 19 March 2012.[51] Sales for the fourth generation in the US began in February 2012 for models including the GS 350 and GS 350 F Sport, with the hybrid version following several months after.[52] A smaller-displacement model, the GS 250 (GRL11), was shown at the 2011 Auto Guangzhou, targeted for sales in China, Japan, Australia and the UK, but not the US.[5]
The GS 450h (GWL10), rated at 343 hp and now using an Atkinson cycle design, has a 35 percent improvement in fuel economy over the previous generation GS 450h, and has a higher combined EPA fuel efficiency rating (31 mpg) than the 306 horsepower GS 350 (23 mpg).[53] Trunk space is improved both for the hybrid and standard models.[47] The GS 450h features standard full LED headlamps[54] and a bamboo trimmed interior.[55] The vehicle was unveiled at the 2011 Frankfurt Motor Show.[56]
For the 2014 model year, changes to GS 350 includes an eight-speed automatic transmission for rear-wheel drive (RWD) models, introduction of F SPORT package (optional Lexus Dynamic Handling system with dynamic rear steering (DRS), electric power steering, variable gear ratio steering (VGRS)), integrated Siri Eyes Free mode from Apple (compatible with iPhone 4S and newer), flush mounted sensors for available intuitive park assist, full color display added to the optional head-up display, available blind spot monitor adds rear cross traffic alert and power-folding mirrors, Luxury Package changes (LED foglamps, Superchrome finish for 18-inch wheels, and the rear armrest control panel display adds display option to view radio station and song title information), optional power trunk opener, Lexus Night View system discontinued.[57]
The GS 300h hybrid model includes a 2.5-liter Atkinson cycle inline-four engine with a D-4S direct injection technology, derived from the third generation IS. The vehicle was unveiled at the 2013 Shanghai Motor Show.[58] The vehicle went on sale in China, Europe, Asia, Australia, and New Zealand, but not in the US.[59]
It is a version of Lexus GS 300h for European market, with 2.5-liter Atkinson cycle four-cylinder engine (181PS), two electric motors, a hard-drive navigation system with a 12.3-inch Monitor and Lexus Connected Services, Mark Levinson audio system, DVD player and rear-view camera with a monitor, among other features. The vehicle went on sale on 11 January 2014.[60][61]
GS F
The high performance "F" version of the GS, the GS F, was unveiled at the 2015 North American International Auto Show. It went on sale in the United States in November 2015 for the 2016 model year.[67]
The GS F features a 5.0 L 2UR-GSE V8 engine with Atkinson cycle at cruising speeds, delivering a maximum output of 473 PS at 7100 rpm and 389 lbft of torque at 4800–5600 rpm. It is paired with a Toyota AA80E 8-speed transmission built by Aisin. The GS F is equipped with Brembo four-wheel power assisted disc brakes with anti-lock braking system (ABS), electronic brake force distribution (EBD) and brake assist (BA), vertical G-sensor for VDIM, rear Torsen or Torque Vectoring Differential (TVD) with three operating modes (Standard, Slalom, or Track), monotube gas-filled shock absorbers and ball-jointed stabilizer bars, spindle grille with F-mesh pattern on the lower half, raised front hood, front cooling ducts, front fender ducts in the L shape, exclusive combination meters from LFA (a large centrally mounted tachometer that alters according to drive mode, digital and analog speedometer, differential torque vectoring monitor, G-force meter, oil and water temperature gauges, mileage information and a stopwatch), and an elliptical cross-section thick grip steering wheel.
