The world debut of the new Lexus LS 500h introduces breakthrough technology that transforms hybrid powertrain performance and driver appeal
The full hybrid version of the new Lexus flagship sedan, unveiled at the Geneva Motor Show, presents the brave design, exhilarating performance and a sophisticated appeal to capture the imagination of forward-thinking customers.
The LS 500h is equipped with the new Lexus Multi-Stage Hybrid System, combining a 3.5-litre dual VVT-i (intelligent variable valve timing) V6 petrol engine with two electric motors, together delivering a total output of 264kW.
The advanced Lexus hybrid system provides improved responsiveness and more rewarding, linear acceleration, particularly when moving off from stationary with 0-100km/h acceleration in 5.4 seconds while further improving the technology’s inherent fuel and emissions efficiency.
A simulated shift control pattern that delivers the feel of driving with a 10-speed gearbox allows for high-speed cruising at lower engine revs. The LS 500h is also capable of running at higher speeds – up to 140km/h – with the petrol engine shut off.
The unveiling of the new hybrid model follows the premiere appearance of the twin-turbo petrol V6-powered LS 500 at the 2017 North American International Auto Show in Detroit. Its highly efficient turbocharger, fast-combustion technology and 10-speed automatic transmission – a first for a luxury sedan – combine to produce a V8-rivalling output of 310kW and a maximum 600Nm of torque, together with notable fuel efficiency.
The LS500h is a further manifestation of how Lexus has reimagined the luxury sedan.
Conceived as the new global pinnacle of the Lexus brand, the LS goes beyond what the world expects from a luxury car. Chief Engineer Toshio Asahi explained: “Developing such a flagship model required a massive paradigm shift. Rather than being bound by the conventions that had defined luxury cars in the past, we aimed to create a car with an innovative, emotional and sensual appeal that would draw customers’ eyes away from other luxury cars and provide entirely new values.”
The LS 500h’s V6 petrol engine makes optimal use of dual VVT-i with valve timing precisely gauged in line with driving conditions, helping secure high torque at all engine speeds.
Measures to reduce friction losses and thus improve engine efficiency include the adoption of narrow, lightweight roller rocker arms and low-friction timing chains, while D-4S direct fuel injection helps create optimum combustion conditions, contributing to good fuel economy.
The four-stage shifting device, added to the combination of the 3.5-litre V6 petrol engine and two electric motors, results in more direct response to driver inputs and an elevation of dynamic performance and driving pleasure. At the same time, it maintains the characteristic smoothness and efficiency for which Lexus hybrids are renowned.
In a conventional full hybrid vehicle, engine output is boosted by the electric motor via a reduction gear; but, with the new Multi-Stage Hybrid System, the power from the V6 engine and the hybrid battery can be amplified by the four-stage shifting device, allowing much greater drive power to be generated when accelerating from stationary.
The design of the system places the multi-stage shift unit immediately behind the power split device, on an axis aligned with the engine crankshaft. Although the unit has four speeds, the D range has a simulated shift control pattern that delivers the feel of driving with a 10-speed gearbox.
As vehicle speed rises, engine speed increases with a linear, direct and continuous acceleration feel, free from the “rubber band” effect witnessed in some continuously variable transmissions. In the 10th gear range, the CVT control allows for high-speed cruising at lower engine rpm for quiet, smooth and fuel-efficient performance.
The transmission further benefits from an improved version of the artificial intelligence shift control found in conventional automatics. This enables intelligent, optimum gear selection to be made in line with driving conditions and driver inputs, for example when going up or downhill.
The system also includes DMI (Driver’s Mind Index), which can adjust gear shifts to suit the driver’s style and behaviour without them having to select a different drive mode to get the kind of performance they want from the transmission.
The Multi-Stage Hybrid System’s design enables the driver to take advantage of an M mode to select and hold gears manually using paddle shifts mounted on the steering wheel – a function not previously available on a Lexus hybrid.
Thanks to the coordinated control of the power-split device and the gear-shifting mechanism, the gear shift will start instantaneously with the computer receiving the signal from the paddle shift, giving an exceptionally quick response.
Lithium-ion hybrid battery
The LS 500h is fitted with a compact, lightweight, lithium-ion hybrid battery. It is 20-per-cent smaller than the nickel-metal hydride unit featured in the current Lexus LS 600h, yet has a higher power density. It increases the luggage capacity by 25 litres (versus LS 600h).
Lithium-ion technology also results in less weight, helping reduce the car’s mass to support overall fuel economy, emissions performance and handling balance.
First announced for the LC 500h, the Lexus hybrid battery features a satellite construction design in which the cell voltage monitoring function has been made separate from the battery ECU. This allows for efficient use of what would otherwise be empty space inside the battery pack to house the wiring harness and battery cooling blower, thus reducing the unit’s overall dimensions. The cooling blower itself has been made thinner yet more powerful.
The LS 500h is built on the new Lexus Global Architecture – Luxury (GA-L) platform, which made its debut in the LC coupe and now, with a longer wheelbase, underpins the new LS.
The GA-L platform is the stiffest Lexus has yet created, providing a perfect foundation for improving handling, ride smoothness and cabin quietness.
It ensures a low centre of gravity and optimum weight distribution, contributing to the car’s essential stability and handling agility, which provides a more rewarding and engaging experience at the wheel for the driver.
Lexus also took the opportunity to improve the already outstanding suspension compliance of the LS. The fundamental high rigidity of the chassis allows the new multilink suspension to be tuned to achieve the great handling performance and supreme ride comfort for which the LS is renowned.
The front suspension system has double ball joints on the upper and lower arms to permit control of the smallest movements from driver inputs and road conditions. Beyond sharing the workload, this arrangement helps optimise suspension geometry to increase wheel control and gain more precise steering response with better initial effort. At the rear, these ball joints are replaced by bushes to ensure superior ride comfort.
To reduce unsprung weight, and thereby promote agility and comfort, aluminium is used extensively in the suspension’s construction.
Adaptive variable suspension, air suspension and the co-ordination of braking, steering and stability systems through Lexus Dynamic Handling all help secure better ride comfort, rear stability and handling.
New advanced safety systems
Advanced technologies are further used to deliver impressive safety performance. The Lexus Safety System+ combines information from omnidirectional sensors around the vehicle, including stereo cameras, that monitor all operating situations from parking manoeuvres to collision avoidance. It helps prevent accidents happening, covering the risks presented by common types of accidents such as rear-end collisions, collisions with pedestrians and accidents caused by lane departure.
If a pedestrian is detected on the road ahead and a collision is imminent, this system will automatically apply the car’s brakes. The driver will be alerted to the system’s operation by a warning on the colour head-up display.
The robust structure of the LS has been enhanced to provide a high degree of passive safety to protect occupants in a collision, using new bonding technology, lighter high-tensile strength materials and aluminium bumper reinforcement.
Following the “Yet” philosophy that has guided the design thinking for successive generations of the LS, Lexus has created a design that offers the room and comfort of a long-wheelbase prestige sedan, yet with the stylish silhouette of a four-door coupe.
Lexus designers took full advantage of the opportunity provided by the low centre of gravity and optimum weight distribution from the LS’s new GA-L platform to produce a lower profile and a long wheelbase, giving the car a stretched, ground-hugging appearance.
The new LS 500h is offered only in long-wheelbase form. At 3,125mm, it is 35mm longer than the current long-wheelbase LS 600h L. The new model sits about 15mm lower than the current LS, while the bonnet and boot are 30 and 40mm lower respectively.
The LS is the first Lexus sedan to feature a six-sided window design, marking a break with tradition. This approach has helped achieve a sleek silhouette and a low-lying fluidity in the design. The LS is also the first Lexus to be fitted with flush-surface windows that integrate smoothly with the side pillars.
The LS displays a unique rendition of the signature spindle grille, designed to convey an aura of dignity that befits the model’s position at the pinnacle of the Lexus brand. The grille has a mesh texture that appears to change in different light, created through months of intense CAD development and the hand-adjustment of thousands of individual surfaces to gain the optimum effect.
Luxury interior inspired by Japanese hospitality
The LS cabin has benefited from an equally new approach, interpreting Japanese aesthetics and craftsmanship traditions in the context of an advanced, luxurious and innovative vehicle interior. Notably, the LS 500 was honoured at NAIAS with the EyesOn Design Award for excellence in interior design.
Omotenashi, expressing the unique sense of Japanese hospitality, defines the LS 500h’s whisper-quiet and luxurious interior and delivers a cabin that welcomes and envelops the occupants and treats the driver like a partner. The key words were “progressive comfort”.
New seat designs, including 28-way power front seats with heating, cooling and massage functions, exemplify this approach. There is also an available rear-seat arrangement that includes an extending leg ottoman and the most generous leg room of any LS generation.
The organically shaped dashboard design clusters information displays at a uniform height so the driver can operate all systems without having to change posture. In addition to a 12.3-inch navigation display, the LS will be fitted with a 24-inch colour head-up display – the largest in the world – that projects a variety of key vehicle information and performance data into the driver’s forward line of vision.
The infotainment system adopts the next generation of the Lexus Remote Touch control system. Its intuitive operation is designed to mirror the way a smartphone is used.
Active Noise Control quietens the cabin by detecting the sound of the engine coming into the vehicle and cancelling certain frequencies, using antiphase sound from the audio speakers.
The serenity of the cabin provides an ideal stage for the Mark Levinson premium audio system that features a sophisticated “Quantum Logic Immersion” sound tuning technology and ceiling array, creating a 3D surround audio for a concert-like experience.
Lexus Takumi craftsmanship also contributes to the special quality of the LS 500h’s cabin, in luxurious new trims, materials and detailing, including new origami-inspired hand-pleated door trims and hand-crafted designs created by Kiriko artisan glassworkers for the inner door panels.
The new Lexus LS 500h is expected to arrive in South Africa in the first quarter of 2018.