Powertrain Smoothness

The original luxury disruptor, the Lexus LS has for nearly three decades set benchmarks for powertrain smoothness, ride quietness, craftsmanship, attention to detail, documented dependability and long-term quality. The Lexus brand supported that groundbreaking vehicle by setting and maintaining new standards for customer experience and satisfaction. Now, Lexus is repeating history with the introduction of the all-new, fifth-generation LS flagship sedan for 2018. Inside and out, the new LS reflects a strong, uniquely Japanese identity and approach to luxury and offers innovative technology with a human touch. Yet the all-new LS is designed to be the brand’s latest global citizen, available in over 90 countries.

Longer and lower than the model it replaces, the all-new LS debuts a strikingly sleek and bold design with a coupe-like silhouette punctuated by the unique Lexus design language. A new driver-centric performance feel stems from building the LS on the company’s all-new global architecture for luxury vehicles (GA-L). This premium rear-wheel drive platform, and offers a more dynamic driving experience while further elevating renowned Lexus comfort.

The original Lexus LS won acclaim by anticipating what luxury customers would want, rather than by simply amplifying what established luxury automobile brands offered at the time. In that spirit, the 2018 LS sedan’s spacious cabin, unique appointments, and visionary technology will once again surprise customers by resetting expectations for a global flagship sedan.

The original LS launched the Lexus brand and the all-new 2018 LS advances the brand’s more dynamic direction. Each generation of LS sedan leading up to the all-new 2018 iteration has elevated the state of luxury, craftsmanship, performance and safety in its own way. To create the 2018 LS, Lexus took the approach of starting from new, reimagining what a flagship sedan should be, as if launching the brand once again. The goal was not to just improve on what Lexus had done, but to exceed expectations of global luxury customers.

A common thread through all LS models remains: Omotenashi, the concept of Japanese hospitality. Applied to a luxury automobile, it means adopting a human-focused approach to the vehicle: taking care of the driver and passengers, anticipating their needs, attending to their comfort and helping to protect them from hazards.

Lexus designers took full advantage of the new platform, with its lower profile and length on par with that of a prestige long-wheelbase sedan, to give the new LS a stretched, ground-hugging appearance. Compared to the outgoing LS, the new model is about 0.6 inches lower, while the hood and trunk are approximately 1.2 inches and 1.6 inches lower, respectively.

Following the “Yet” philosophy that has been passed on since the first-generation LS, Lexus created a design offering the room and comfort of a prestige “three-box” sedan, yet with the more striking coupe-like silhouette that holds stronger appeal for many of today’s luxury customers. The new LS is also the first Lexus sedan with a six-window profile, which enables excellent outward visibility. A first for a Lexus sedan, the flush-surface windows smoothly integrate with the side pillar.

The unique rendition of the spindle grille mesh, with a texture that seemingly changes in changing light, is the result of both intense CAD development and hand-adjusting thousands of individual surfaces. Flanking the unique grille, the narrow slit-like 3-projector lamp merges with an L-shaped LED lamp that wraps broadly around to the side to give the front of the LS a resolute gaze.

The coupe-like silhouette is not due solely to the fastback roof style. Maximizing the GA-L platform’s low form, the pillars of the cabin taper from the central position of the occupants. Together with the contrast between the pulled-in doors and the front and rear fenders that flare away from the central position of the occupants, this creates a dynamic form.

A front to the rear shoulder line gives the vehicle’s basic posture a low stance with a horizontal axis and a bold appearance. Additionally, the axes of the dramatically flared front and rear fenders are slanted forwards, creating a dynamic impression that evokes driving performance. An outer slide-type moon-roof preserves headroom with the lower roofline.

The 2018 LS debuts two new 19-inch wheel designs and three 20-inch wheel designs, two of which are also new. The 20-inch premium wheels employ a brilliant appearance created using an electroplating technique known as sputtering. All but one (F SPORT) of the new wheel designs feature a hollow rim structure that helps reduce resonant sounds generated by the tires. More than ever before, luxury sedan drivers demand greater handling agility and performance feel, but without sacrificing comfort. It’s one of the most difficult balances to achieve in a vehicle, yet the new Lexus GA–L platform easily meets this challenge.

The GA-L platform is the stiffest in Lexus history, setting the stage for enhanced handling, ride smoothness and cabin quietness. The 123-inch wheelbase is 1.3-inch longer than the outgoing LS long-wheelbase model. The new wide and low LS design optimizes the center of gravity and weight distribution.

Helping to provide the uncanny ride and handling balance in the new LS is the latest generation of a chassis control technology: Vehicle Dynamics Integrated Management (VDIM), which was first introduced in 2005. This system implements cooperative control of all available vehicle subsystems— ABS, Traction Control (TRAC/TRC), Vehicle Stability Control (VSC) and Electric Power Steering (EPS), Variable Gear Ratio Steering (VGRS) and Dynamic Rear Steering (DRS)—to control basic longitudinal, lateral and vertical motion as well as yaw, roll and pitch.

The all-new GA-L vehicle architecture that underpins the LS is the result of a completely new approach to engineering, materials and loads of the vehicle structure. Rather than starting from existing vehicle platform and then figuring out how to modify it to fit the LS’ shape and strengthen it to support contemporary chassis dynamics, Lexus engineers literally started with a clean sheet of paper – a blank CAD screen– in designing the new structure.

Examples of this can be easily seen under-hood, where new cast-aluminum suspension towers that support the upper spring seats and suspension mounts are visible above each front wheel. Since aluminum and steel can’t be welded together with conventional techniques, the joint attaching the aluminum tower casting to the steel body structure is made with self-piercing rivets and high-strength adhesive bonding; similar processes are used to secure the aluminum rear suspension towers to the body structure behind the back seats. Compared to structures with similar capabilities in steel, this technology is 42 percent lighter at the front; in the rear the aluminum structure has 1.5 times the rigidity of steel with 50 percent less weight.

In creating the new LS, engineers used lightweight materials including ultra-high tensile hot stamped steel and other steel alloys in critical areas with tensile strengths from 590 up to 1180 MPa and aluminum. The 2018 LS has a high tensile steel mass composition of nearly 30 percent, which is more than double what was present in the previous-generation LS (14.1 percent).

A combination of special body adhesive and the use of Laser Screw Welding, a proprietary laser welding process proven on other recent Lexus models, increases panel joint rigidity and gives the LS a feeling of exceptional strength and solidity.

Critical to its driving performance, the new platform lowers the vehicle’s center of gravity by placing most of its mass, including the engine and the occupants in positions more centralized and lower in the chassis. Special braces in the engine compartment, stiff aluminum front and rear suspension towers, and other features help bolster the strength of key chassis structures.

LS models have long set benchmarks for suspension compliance, yet even here Lexus saw opportunity for further gains. For example, the all-new multilink front suspension employs double ball joints on the upper and lower control arms to help allow for control of the smallest movements from the driver inputs and road conditions. This unique dual-ball joint arrangement optimizes suspension geometry to increase wheel control and yield more precise steering response with better initial effort. To reduce un-sprung weight and aid agility and comfort, aluminum is used extensively in the suspension.

Like the previous LS, the all-new model offers an available air suspension system that further refines the already sublime ride quality. A new, more advanced version of Adaptive Variable Suspension (AVS) continually adjusts damping control in response to driving operations and road surface conditions. “Continually” is the key word; because Lexus increased the damping-force switching levels from the previous model’s nine to 650 in the 2018 LS. The result is faster, more seamless and refined operation.

For high power, scintillating performance and excellent fuel efficiency, Lexus designed an all-new 60-degree 3.5-liter V6 engine specifically for the new LS. This engine has an under-square design for improved thermal efficiency coupled with twin turbochargers, and has benefitted from the company’s F1 technology. This new LS engine is indicative of the more dynamic approach being taken by Lexus, offering V8-level power in a more compact package with efficiency and refinement.

The new LS engine offers the output one would expect in a flagship sedan: 416 horsepower and 442 lb-ft of torque, significant gains over the outgoing LS model’s naturally aspirated 4.6-liter V8 (386 hp and 367 lb-ft). The engine’s long stroke, optimized 0.86 bore-to-stroke ratio, increased valve angle, straight intake ports and laser-clad intake valve seats developed using performance simulations based on F1 technology combine to yield world top-level high-speed combustion technology and thermal efficiency.

The twin turbochargers were designed and produced in-house to control tolerances and quality. They achieve top-level mechanical efficiency by improving exhaust energy recovery using a curved turbine blade shape and increased blade length, along with die-cast compressor housings and improved surface precision. Electric waste-gates provide ultra-precise turbo boost control for seamless, lag-free power buildup. The intercoolers are cooled by engine coolant for higher performance and efficiency.

A special version of Lexus’ D-4S gasoline direct injection plus port injection system was developed to improve injection control linked to turbocharger operation. Called D-4ST, this system controls new six-hole direct injectors and the port fuel injectors to take advantage of the turbochargers and the high tumble ratio of the engine. Twin water-to-air intercoolers reduce the temperature of air pressurized by turbocharging. The intercoolers are mounted on top of the engine, each in a direct path between its turbocharger and intake throttle to reduce volume and lag in the intake tract.

Remarkable powertrain smoothness, a Lexus hallmark, begins deep inside the cylinder block, where a ladder frame support for the crankshaft main bearings adds rigidity for low vibration. Redesigned engine mounts, the electric waste-gates and numerous other features also contribute to the engine’s ultra-smooth demeanor.

In RWD form, the new LS 500 sees a 0-60 time of 4.6 seconds. Perhaps more critical to driving enjoyment, though, is how Lexus tuned the engine and transmission to deliver instant acceleration and a constant buildup of torque toward the engine’s redline. The driver can tailor powertrain response and feel by choosing from Normal, Sport S or Sport S+ modes. Just enough of the exhaust note can be heard to enhance the car’s dynamic nature.

The first-ever 10-speed automatic transmission for a premium passenger car, having debuted in the Lexus LC 500, is now also used in the new LS 500 gas models. It is a torque converter automatic, yet with shift times that rival those of dual-clutch transmissions. The wide bandwidth afforded by 10 closely spaced ratios is ideal for all driving situations. Using aluminum for the clutch drum, clutch hub and planetary carrier reduce rotating mass; coupled with shortened internal oil passages and smaller, faster shift solenoids results in quicker shifts. These improvements, plus a resin plastic transmission oil pan, yield a 10-speed transmission weighing the same as the previous 8-speed gearbox.

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