Lexus steer-by-wire: driving reinvented

• Lexus-first steer-by-wire system debuts in the new RZ electric SUV
• Performance reinforces the Lexus Driving Signature – driver confidence, control and comfort at all times
• Innovation with multiple rewards – precision, responsiveness and constant sense of connection between the driver and the road
• A core technology in the delivery of next-level autonomous driving
• Steering inputs transmitted as electronic signals to the front wheels, with prompt and direct response, strengthening the dialogue between driver and car
• New-design compact steering wheel with hand and-over-hand wheel turning almost eliminated
• System communicates relevant feedback from the tyres, with unwanted vibrations filtered out
• Steer-by-wire and Lexus’s DIRECT4 electric all-wheel drive synchronise to elevate the driving experience

Lexus has a proud history of technical innovation. It constantly explores opportunities to raise levels of safety, performance, comfort and, not least, driver rewards. It’s in this spirit that it has successfully introduced the Lexus-first steer-by-wire system, a radical technology that brings a new dimension to the driving experience.

Making its debut in the new RZ electric luxury SUV, Lexus steer-by-wire offers a duality of rewards. It delivers the control, precision and instant, faithful response that are valued by the world’s top professional drivers. At the same time, it is smooth and easy to use and generates a reassuring sense of constant connection with the road, building the driver’s dialogue with their vehicle and enhancing the pure pleasure of being at the wheel.

As well as being responsive and intuitive to operate, the system filters out unwanted vibration, opens up the cockpit for a clearer forward view and enhances the driving experience.

Futhermore, steer-by-wire is also a core technology in the development of next-level autonomous driving.

The technology: steering by electronic signals

Unlike a conventional mechanical steering system, Lexus’s steer-by-wire has no mechanical connection between the steering wheel and the front wheels. Instead, the driver’s steering inputs are communicated as electronic signals, relayed via a steering torque actuator to a steering control actuator on the front axle. Response is quick and direct, inspiring confidence.

Safeguards are in place, with a back-up system that will intervene immediately to provide uninterrupted performance, should the steering system experience any issues.

The new-look steering wheel

The driver uses a compact, new-look steering wheel. Designed without the traditional upper and lower curved sections, it is visually like the controls found in an aircraft. This not simply a design exercise: steer-by-wire allows for the lock-to-lock turn angle to be set to plus or minus 200 degrees. Steering thus becomes easier, with the need for hand-over-hand turns almost eliminated. Just small movements are all that’s required, with the driver “aiming” the car in the direction they want to travel.

The wheel’s compact dimensions have allowed for the driver’s cockpit to be opened up, with a clearer, uninterrupted view of the road ahead and more space between the wheel and their legs.

This further enhances the fundamental qualities of the “Tazuna” concept cockpit design, which prioritises the driver’s forward focus by organising controls, instruments and information displays so they can be used with minimal movement of hand or eye.

Steering that adapts to the situation

Lexus’s steer-by-wire has the added benefit of a variable steering gear ratio that automatically optimises performance according to vehicle speed.

Steering operates at a lower ratio in low-speed situations, making manoeuvring effortless when turning at an intersection or navigating a parking space. At medium speeds, for example when driving on winding roads, only minimal inputs are required for nimble, exhilarating and fun-to-drive performance. And at high speed, the ratio is automatically increased to promote stable vehicle behaviour and a confident driving experience.

Feedback from the road

As well as receiving electronic signals from the steering wheel, the Steering Control Actuator senses forces generated from the road surface. It is able to filter out unwanted vibrations, for example from the brakes or generated by sudden tyre movements on uneven surfaces, and transmit feedback to the steering wheel via the Steering Torque Actuator.

This means the driver still receives authentic and accurate feedback. A clear steering feel gives them a constant sense of connection with the road and a natural sense of how the car is behaving.

With steer-by-wire, the wheels are also less likely to move contrary to the driver’s intention, even when driving on slopes.

Compatibility with battery electric technology

As well as being able to adjust operation according to the driving situation, the steer-by-wire works in combination with Lexus’s precise and highly responsive DIRECT4 electric all-wheel drive system. Together, they produce closer, more rewarding synchronisation of the driver’s actions and the car’s behaviour, raising the level of driving rewards.

Lexus steer-by-wire is available now, provided as standard on the new RZ 550e F Sport and F Sport Takumi models, together with DIRECT4 electric all-wheel drive and the groundbreaking new Interactive Manual Drive.

ENDS