Although it has previously been implemented in some limited-run or concept vehicles, steer-by-wire (SbW) is only now starting to gain significant momentum. The technology removes the traditional steering column that turns a vehicle’s wheels mechanically and replaces it with a digital system of electronic control units (ECUs) and cable networks. Electric models already featuring SbW include the Lotus Eletre, Tesla Cybertruck, and Nio ET9.
Danilo Teobaldi, Principal Chief Engineer at Nio, tells Automotive World that SbW is primarily valuable for addressing basic issues like unwanted vibrations, delayed response, and wear and tear; but it also marks a step forward in other aspects like safety, comfort, and adaptability. “SbW provides a variable steering ratio that optimises handling, offering maximum manoeuvrability at low speeds and superior stability at high speeds, and thereby providing both comfort and an uncompromised driving experience.”
Importantly, SbW is highly complementary with software-defined vehicle (SDV) concepts under development today. Removing mechanical linkages creates more interior space for infotainment experiences, while fully digital steering opens the door for next-generation automated and autonomous driving systems. “It paves the way for delivering a more personalised and dynamic driving experience,” states Teobaldi.
Safe and scalable
The Nio ET9, deliveries of which commenced in March 2025, integrates SbW from ZF into its SkyRide intelligent chassis. Jake Morris, SbW Portfolio Director at ZF, explains that his company’s technology is a scalable and modular system that provides OEMs with a simple and adaptable conversion process.
“This is particularly important for existing and future vehicle architectures—it is conceivable that a single central high-performance computer will control the SbW system in concert with all other driving dynamics functions.” ZF is demonstrating what this could look like with its cubiX software platform and Chassis 2.0 concept, an all-in-one vehicle system combining smart actuators with software applications and intelligent chassis architectures. “Steering becomes electric, intelligent, software-based and interconnected, just like the cars of the future,” says Morris. Through this highly configurable concept, the characteristics of a specific model or an entire brand can be controlled entirely through software.
In terms of safety, SbW systems eliminate mechanical connections that could fail and replace them with ECUs for redundancy, ensuring the vehicle remains controllable even if part of the system fails. “This intrinsic safety is vital for the reliability of SDVs, which must operate flawlessly under all conditions,” he states. Compared to legacy systems, Nio claims the ET9’s digital steering has more precise control and reduced delay, minimising the risk of skidding or loss of traction.
Morris notes that SbW systems can also be scaled across different vehicle models and platforms, making them a versatile solution for various types of vehicles, from compact urban cars to luxury SUVs. By removing mechanical complexity, SDVs subsequently become easier and more cost effective to produce. For example, manufacturing right-hand-drive variants for markets like the UK, Australia, Japan, and India would simply require installing a steering wheel actuator on the other side of the cockpit.
Updateable steering
Over-the-air (OTA) updates are increasingly touted as the core benefit and most important attribute of SDVs. Teobaldi states that SbW intersects neatly with this trend in the Nio ET9: “The whole base-function calibrations can be updated OTA, improving the low-speed manoeuvrability, mid-speed agility, and the high-speed stability.”
Instead of relying solely on automatic brake systems, the ET9 uses both front and rear steering adjustments to maintain control—for example, to stabilise the car if a tyre blows out. “This smart steering system can be continuously improved and updated, allowing new safety features to be developed, validated, and eventually provided to the user without physical changes.” OTA could also be used to deliver value-add functions like adaptive steering settings that automatically adjust based on driving style, road conditions, or environmental factors to ensure optimal performance in a variety of scenarios.
“SbW and OTA combine with Nio’s SDV architecture to provide the digital foundation that enables continuous evolution and allows for real-time customisation and improvement,” says Teobaldi. Morris agrees, calling updateable SbW the “cornerstone” of next-generation vehicles that will facilitate enhanced customisation, deeper ADAS integration, improved diagnostics, and enhanced safety.
SDVs […] must operate flawlessly under all conditions
Going forward, the effectiveness of SbW could beget fully interconnected vehicle control systems, incorporating brake-by-wire and throttle-by-wire. This would result in a fully software-controlled vehicle. This new paradigm will be a substantial boost for both electric vehicle manufacturers and SDV developers seeking energy conservation through greater system efficiency. “This evolution will not only enhance the driving experience but also pave the way for more advanced, safe, and efficient vehicles,” says Morris.
Foundation for next-gen vehicles
Perhaps the most exciting consequence of SbW could be the realisation of fully autonomous vehicles (AVs). Competition in both the private vehicle and robotaxi markets is heating up, but while sensor tech receives a lot of attention, updateable digital steering systems could prove to be the unsung hero. Morris considers the technology an integral to any system SAE Level 2 and above, meaning one in which the computer must have full control over the vehicle’s dynamics.
Teobaldi calls updateable SbW wire systems nothing less than “crucial” for the future of AVs. “SbW can incorporate the latest sensor technologies, control algorithms and safety enhancements, ensuring that autonomous functionalities continue to improve and adapt to emerging standards.” This flexibility will be vital for maintaining high safety and performance levels in a rapidly advancing field. Morris is even more expansive: while calling a SbW a “pivotal component” that will be key enabler for specific applications like robotaxis, he believes it might ultimately reshape vehicles themselves.
“SbW systems free up valuable space within the vehicle. This allows for more innovative interior designs and better utilisation of space, which is especially important for electric vehicles and AVs, where every inch of space can be optimised for passenger comfort and additional technology,” says Morris. In the cabin of highly automated vehicles, the steering wheel could even retract into the dashboard to create an effective ‘living room on wheels’.
By setting a new benchmark in precision and adaptability, Teobaldi positions SbW as a core pillar in Nio’s strategy to be at the forefront of smart, software-defined electric mobility. Morris, taking a broader perspective, calls SbW more than just an innovation in vehicle steering: “It is a foundational element for the next generation of SDVs. By enhancing integration with software control, offering customisation and flexibility, optimising space, improving safety and supporting advanced mobility solutions, SbW systems are set to revolutionise the automotive industry and drive the future of mobility,” he concludes.
