Lexus breaks cover its first full-electric model in the Philippines the form of the all-new RZ 450e

First and foremost, the RZ is a Lexus, retaining all the fine qualities of performance and craftsmanship associated with the brand. The company has leveraged its wealth of vehicle electrification experience to deliver the benefits of a BEV with the essential refinement and driving experience that are unique to its brand.

The RZ also possesses new e-Axles, the compact motor units used front and rear that work in conjunction with new DIRECT4 all-wheel electronic drive torque control. High-quality handling and responsiveness are secured with a dedicated new electric vehicle platform, which brings excellent body rigidity, a low centre of gravity and a long wheelbase. A powerful lithium-ion battery unit is fully integrated in the chassis, beneath the cabin floor, its quality finely controlled to ensure performance is maintained long-term.

The platform and battery electric drivetrain also open up new freedoms in design. The exterior reinterprets the signature Lexus spindle shape in the vehicle’s body, while the interior is a light and open space that is both simple and luxurious, expressing Lexus Omotenashi hospitality and Takumi craftsmanship.

With its zero-emission performance, the RZ will help Lexus in its progress towards carbon neutrality and a sustainable mobility society. Here, the focus is not just on the car’s performance on the road; it embraces its entire lifecycle, from parts procurement, manufacturing and ownership through to eventual disposal. Already new methods have been adopted at Lexus’ Motomachi factory, the RZ production centre, in the processes that produce the highest emissions.

EXTERIOR DESIGN

Building a car on an all-new battery electric platform opened up new design opportunities and the freedom to create a look that sets the RZ 450e apart from other vehicles. At the same time, its styling is an evolution of Lexus “Next Chapter” design, embracing themes that can be seen in other new Lexus models, such as the RX.

The basic theme was seamless, emotional design inspired by the experience of driving a BEV. The RZ is instantly recognizable as both a Lexus and a BEV, with proportions that reflect its dynamic character. The new, dedicated BEV platform and electric powertrain give the RZ a lower centre of gravity and allow for a lower nose profile. This is the starting point for a silhouette that flows through a smooth cabin section to a rearward peak in the roofline, giving more head room (67 mm) for rear seat passengers. A sleek horizontal door axis accentuates the long wheelbase and the large diameter 20-inch wheels are pushed out to the corners, expressing a wide stance and the low centre of gravity.

The RZ measures 4,805 mm long, with a 2,850 mm wheelbase and short overhangs – 975 mm front, 980 mm rear. Overall height is 1,635 mm and the width is 1,895 mm (excluding door mirrors). In terms of external dimensions and footprint, the model sits between Lexus’ mid-size NX and large RX crossover models.

From the side view, the design creates volume around the front wheels, illustrating the power in the front axle, while the rear wheels are pushed back to give a “torqueful” look. The doors have contrasting forms and striking surface treatments, creating a seamless visual sweep from front to rear.

As with the recently launched all-new RX, the design sees the familiar spindle grille shape more deeply integrated into the complete frontal design, generating a stronger three-dimensional effect. As the electric powertrain requires less cooling airflow than a combustion engine, the familiar grille has been dispensed with. The area is instead finished in the car’s body colour, while the position of the slim headlamps and the blacking out of the bumper corners add emphasis to the central spindle shape, establishing a distinctive Lexus BEV look.

The new-design headlight units are unified with the spindle body. Ultra-slim, they accentuate the Lexus L-motif of the daytime running lights, while the principal headlight lamps and turn indicators are made less prominent.

The rear presents a cool, high-tech look with a split roof spoiler that extends the design’s rearward flow and contributes to the car’s stable performance.

The elongated LED light bar across the width of the car has become a hallmark feature of Lexus design. Here it wraps around the muscular rear quarters with a geometric pattern and has an exceptionally thin centre section that throws the new LEXUS script on the back door into sharp relief. The rear thread is widened to 1,620 mm (+10 mm vs front track), further emphasising the car’s planted look.

AERODUNAMIC FEATURES

Aerodynamic measures were a key focus in achieving a low drag coefficient (0.28 Cd) that would contribute to the car’s energy efficiency.

The cabin shape has been optimised to gain smooth airflow on the outside and comfort inside. The belt moulding sits flush with the bodywork to help regulate the flow of air and keep the car stable. The rear spoiler design contributes to handling and stability in straight-line driving and cross-winds without producing drag. The back door is also shaped to adjust the angle of airflow from the roof, reducing drag and contributing to the driver’s sense of the car being in firm contact with the road.

A fully covered under floor is another drag-reducing factor, the front section with a dimpled surface that helps maintain stability at high speeds and rear featuring fins that direct airflow rearwards from the wheels. The small front grille aperture features shutters that close automatically when cooling air flow into the motor compartment isn’t required.

NEW COLOR OPTIONS

The RZ is launched with a choice of exterior finishes that includes new Aether Metallic, inspired by blue skies, and striking Sonic Copper. It’s also available in Sonic Chrome, Sonic Quartz, Sonic Iridium and Graphite Black. The sonic shades use an advanced paint technology in which pigment particles and metal flakes are highly compressed into micro-thin layers, contributing to deeper, more lustrous finish and stronger light and shade contrasts.

The RZ is available in a new bi-tone design which features a contrast black finish that extends from the front of the car, over the bonnet, pillars, and roof.

WHEELS AND TIRES

The RZ is offered 20-inch wheels. The 20-inch wheels are dark premium metallic finish. Driving stability is supported by using different size tires at the front and rear 235/50R20.

DRIVING PERFORMANCE

• RZ performance delivers the Lexus Driving Signature, characterized by Confidence, Control and Comfort

• Lexus combination of e-Axles and DIRECT4 all-wheel drive torque control

• Highly rigid body founded on new e-TNGA electric vehicle platform supports precise, prompt chassis response

THE LEXUS DRIVING SIGNATURE

Securing the Lexus Driving Signature was the primary goal in the development of the RZ’s dynamic performance and strengthening the car’s core characteristics – the “three Cs” of confidence, control and comfort in all driving situations. Going further, the benefits of BEV-specific qualities, such as fast response and high precision were maximised. To achieve this, Lexus has been able to call its years of pioneering experience in electrified vehicle technologies, going back to the original RX 400h hybrid electric of 2004.

Lexus has ensured the vehicle always responds as the driver intends, making driving both comfortable and exhilarating., even for people who are not used to driving a BEV. The result is the addition of a BEV dimension to the Lexus Driving Signature – the refined, linear and reassuring responsiveness and rewarding feeling of control and connection with the vehicle that define the driving character of new Lexus vehicles.

This is true to the performance concept of “The Natural” adopted by chief engineer Takashi Watanabe and his team during the car’s development. Special attention was paid to giving the driver an excellent sightline and feedback and ensuring precise vehicle posture control, at all times.

BODY STRUCTURE

The RZ’s BEV-specific platform provides an inherently strong foundation on which to construct a vehicle with excellent body rigidity. Advanced techniques have been applied, including laser peening and laser screw welding

for the rocker panels and joint reinforcement to suppress or prevent distortion. Laser welding allows a thicker rocker panel to be used, eliminating the cut-away sections required for spot-welding. Elsewhere, extensive use is made of structural adhesive, laser screw welding and short-pitch welding (at an unprecedented degree) to increase the jointing area and gain higher rigidity.

High-rigidity foam is used in each corner of the back door aperture to strengthen an area that is particularly susceptible to deformation. This also reduces noise and vibration. The rear of the car has a double-annular frame, which helps the car settle after cornering or changing lanes.

At the front, braces and thicker support pillars for the radiator suppress lateral deformation. Rigidity is further enhanced by suspension tower braces and front and rear performance dampers. The driver witnesses the benefits of the car’s rigid structure in straight-line stability and precise handling and steering response, contributing to the control and confidence elements of the Lexus Driving Signature.

WEIGHT-SAVING CONSTRUCTION

Reinforcing the car’s structure increases weight, which in turn has an impact on power consumption and dynamic performance. To counter this, Lexus has used materials and methods to reduce the weight of the frame, helping maintain the driving range without compromising body rigidity. Priority was given to reducing the mass of parts located higher in the vehicle, to preserve a low centre of gravity and suppress body roll when cornering.
For example, lightweight 1470 MPa steel is used for the centre roof reinforcement and a patchwork material for strengthening the front and centre pillar. The bonnet is made of aluminium and the door and wheel arch mouldings and back door garnish are light, moulded resin which uses less material but remains rigid and light.

NOISE AND VIBRATION CONTROL

Although the battery electric drivetrain produces less noise than one with an internal combustion engine, its quiet performance makes noise from the road and the car’s surroundings more noticeable. The RZ’s engineers and designers made it a priority to ensure the cabin environment was appropriately calm and quiet, applying a three- part strategy: controlling the noise; preventing it from entering the cabin; and paying particular attention to noise experienced in the rear seats.

The measures to reduce noise and vibration include an all-round seal for the bonnet, which prevents air flow escaping through gaps, reducing disturbance and sound. Inside the RZ, the thickness of the dashboard inner silence has been gauged to reduce the gap between peripheral parts and achieve better noise insulation and absorption.

The large roof area is a primary source of noise when driving. To address this, a vibration-damping sheet has been added that makes the roof structure more rigid, with a significant impact on NV levels. Other measures include foam coating at the base of the front and centre pillars, acoustic glass in the front and rear doors and the placement of liners and insulation material in the cowl, dashboard, bonnet, wings and wheel arches.

The RZ has a new version of active sound control which uses surround sound to introduce noise-cancelling frequencies into the cabin, via the audio speakers.

DIRECT4 ALL WHEEL DRIVE CONTROL

DIRECT4, an exclusive Lexus technology, is an intelligent system that constantly and seamlessly balances the drive torque between the front and rear axles. The result is stress-free performance and stable handling, with intuitive operation strengthening the sense of connection between driver and machine.

The system uses ECU sensors to collect, evaluate and react to a range of factors, including vehicle speed, steering angle and G forces. From these inputs, it calculates and immediately applies the appropriate drive torque to each e-Axle to maximise grip and traction suitable for the road surface. The front/rear torque bias can be adjusted in milliseconds – faster than any mechanical system.

BATTERY ELECTRIC POWERTRAIN

In developing a new battery electric powertrain, Lexus sought to strike a practical balance between performance and efficiency. To achieve its aims, it was able to apply multiple technology advantages from its experience of developing successful hybrid electric vehicles over the past two decades. Key to this strategy was adoption of an optimally sized battery that delivers the best balance between driving range, efficiency, cost, and size/packaging.

Battery electric powertrain

Lexus has designed a compact, high-voltage system circuit in which a transaxle and inverter are contained within the eAxle units. An Energy Storage Unit (ESU) integrates the charging, power supply and power distribution functions. Noise filters have been added to the circuit to enhance electromagnetic compatibility; this helps avoid interference with the vehicle’s audio system.

The permanent magnet motors have a high-power density and 17,000 rpm rotation speed. The inverter achieveshigh volumetric efficiency while allowing for a high current output. Its compact size – helped by a frame-style construction – allows it to be integrated in the transaxle. The motors are located on a symmetrical three-point aluminium mounting system giving balanced support that contributes to comfort, handling, stability and quiet performance.

Using grille shutters in front the radiator reduces air resistance and gives high cooling performance when required; these automatically close when not required. Ducts in the front grille direct air flow to the radiator, even when the shutters are closed. Cooling performance is provided a single, large-diameter fan.

LITHIUM-ION BATTERY

The battery stack is positioned entirely beneath the cabin floor and forms a structural part of the vehicle’s frame. This contributes to the vehicle’s rigidity and its low centre of gravity, while the unit’s slim profile also means there is no intrusion in cabin or load compartment space. The battery is contained in a sealed, reinforced structure to protect it in the event of contact with the road surface or a collision.

The unit comprises 96 cells with a gross capacity of 71.4 kWh. Quality, durability and reliability are reflected in Lexus guaranteeing that the battery will retain at least 70% of its capacity after 10 years. Lexus is confident however, given its long experience in battery technologies, that actual capacity at the point should be at least 90%.

Most RZ variants – running on 20-inch wheels – achieve a range of around 395 km in the WLTP combined cycle test. Those which use 18-inch wheels see the range extended by about 40 km. These ranges apply to performance from full charge to complete depletion of the battery. However, for peace of mind, the driver’s instrument display will show the remaining range as 0 km from when the battery’s state of charge reaches approximately 8%.

Efficient cooling is key to battery performance and durability. A long-life, high-resistance LLC coolant is used for both the lithium-ion battery and the BEV system. This controls the temperature in a highly efficient system that helps maintain stable battery output even under high loads, such as high-speed cruising or repeated rapid charging. The battery cooling and the car’s air conditioning system work co-operatively, which enhances power performance, ensures cabin comfort and supports longer battery life. The unit is cooled from the bottom with a uniform flow path size for the refrigerant, giving even better cooling performance. The coolant is contained in separate chamber, so there is no direct contact with the battery in the event of a leak.

When operating in colder temperatures, a battery heater can be activated when charging the vehicle. This uses the heater in the air conditioning system and comes into play automatically when using a DC charger.

BATTERY CHARGING

The RZ is equipped with a compact and lightweight 11 kWon-board charger. Battery recharging when connected to a three-phase power supply takes around six-and-a-half hours; using a one-phase supply the time is around 10 hours; connected to a DC fast-charging system, an 80% recharge can be accomplished in about 30 minutes.

To know more about the Lexus RZ, visit the official webbsite.

Photos by Randolph de Leon