► CAR explores drive-by-wire technologies
► Steering, throttle, shift and braking without physical connections
► Which car makers want it, and which ones don’t?
What do cars like the Tesla Cybertruck, a Lexus RZ and most of Ferrari’s line-up have in common? They’re all production cars that use ‘drive-by-wire’ technology – engineering and software that enables control of a car’s movement without the need for a physical engineering.
The technology area has seen an increased amount of focus recently, with many car makers investing millions in research and development – or are working with suppliers that are doing the very same – to figure out how best to apply the technology to its cars.
Drive-by-wire technologies have multiple applications and, it seems, appeals to car brands of all types – from ones that make performance cars to luxury ones, as well as those focusing their efforts on future automation.
Hence why Tesla’s beastly pickup comes pre-built with steer-by-wire tech, while Lexus is offering it as part of its performance-focused RZ F-Sport model. Bosch, meanwhile, is engineering its own proprietary by-wire technologies and is testing them on the road, with CEO Stefan Hartung telling CAR: ‘by-wire technology is a complexity management tool, because it takes that complexity away.’ Fellow German supplier to the automotive industry, ThyssenKrupp, is also heavily investigating by-wire functions and says the tech is ‘on the verge of a breakthrough.’
Ferrari is a whole leap further forward – using brake-by-wire tech in the Purosangue, 12Cilindri, 296 and SF90 – and almost all new cars equipped with automatic gearboxes use shift-by-wire tech.
What are the benefits of drive-by-wire technology?
The main identifying factor of drive-by-wire technology is that it removes most of the physical engineering usually associated with controlling a car. Think components like steering columns and the systems they’re connected to, hydraulics and lines for braking and throttle systems and so on. Steering and braking systems, for example, are instead connected digitally via wiring, processors and software.
Removing physical components allows for two benefits straight away: a reduction in weight and opportunities for better packaging. Many automotive engineers agree that the weight loss is relatively negligible, however, with the opportunity to package interiors better becoming a much more useful opportunity for engineers and car designers.
This use comes into focus more when designing electric cars and vehicles with more automation, enabling more spacious interiors complete with steering wheels that fold away into the dashboard when a car is driving autonomously. A car with a physical steering rack, by comparison, wouldn’t be able to do that so adeptly.
Christoph Starzynski, head of vehicle development at Mercedes-Benz adds: ‘From a packaging perspective, you don’t need a right-hand drive or left-hand drive version of your components, so from a pure manufacturing complexity perspective that’s an advantage.’
Car makers also see this as a benefit when it comes to engaging with the car’s infotainment. ‘In combination with Level 3 conditionally automated driving, [steer-by-wire] will enable an even more immersive entertainment experience in the medium term,’ says Mercedes tech boss Markus Schäfer. ‘That’s because the flat steering wheel provides a better view of the display when streaming your favourite show, for example.’
And that neatly takes us on to our next point: the reduction or customisation of driving effort. Some car makers that are actively pursuing the use of the technology, already have it available or produces cars with its pre-installed are more likely to use a yoke-shaped steering wheel. As well as improving the view of the car’s interior screens, many steer-by-wire systems are calibrated to reduce the amount of turning of a steering wheel required, where a full turn of the wheels requires little actual steering effort.
Reducing effort and providing more precise control is exactly why Ferrari has its own brake-by-wire technology in cars like the SF90, 296 and 12Cilindri. ‘The technology allows us the pedal feel that we want when using the same hardware, meaning we can fit in a GT car, a sports car or anything else,’ says Ferrari vehicle dynamics project lead, Jacopo Canestri. ‘We can break the rules of a standard system with servos because you have leverage in that system; to send more power to the brakes you need more stroke. With by-wire, we can choose less stroke but still have the power we want.’
Francesco Comand, a Ferrari development driver, agrees: ‘it gives us complete freedom at the calibration phase. I believe that this technology, together with ABS Evo in our cars, are two of the most important innovations in braking since carbon ceramics.’
As well as reducing effort, some car makers are investigating its customisability. Ben Payne, vice president of design at Lotus, says steer-by-wire technology can enable a level of personalisation not possible with conventional systems. ‘Because it’s all software driven, you can tune the ratios, the speeds, the feedback… everything,’ he says. ‘You can go from town driving where it’s super light and giving you just enough feedback to track driving with minimal lock for that proper race car feel.’
Does drive-by-wire technology actually work?
Given there are cars that already feature steer-by-wire or brake-by-wire that are on sale now, we’re already inclined to say yes. Even so, the technology has taken years to be refined to the point it is now, with some cars having it in the past and failing to take full advantage. Infiniti, for example, launched its Q50 in 2013 with steer-by-wire technology and it was widely panned for its poor calibrations.
More recently, though, CAR has been privy to testing emerging ‘by-wire’ technologies. For example, three years before it made official production, we were one of the first to test Lexus’ OneMotion Grip steering. The system was designed to reduce the effort required for low-speed manoeuvres and eliminate any vibrations drivers would normally get through the steering wheel.
We’ve also had some seat time in several Bosch development mules, testing both steer-by-wire and brake-by-wire technologies. Bosch has been developing a customisable steer-by-wire system that changes the amount of steering effort based on what drive mode you’re in. It’s also engineered a brake-by-wire setup that uses a fixed pressure pad instead of a conventional pedal; it’s a slightly weird setup, but one we got used to quickly as it presented a level of braking precision and response we’d not experienced before.
There has to be a catch somewhere…
One of the biggest areas of concern is cybersecurity. Naturally, given the car’s fundamental controls are being handed over to software and digital platforms, that can present the opportunity for someone to potentially hack into a car and control it remotely.
Data from analytics provider Upstream, secured by the Institute of the Motor Industry, points to rapid increases in automotive cyberattacks in 2023: around 35 per cent of attacks focused on telematics data and apps, but 14 per cent targeted electronic control units in cars – devices that will be needed to control by-wire systems – and it’s a growing metric.
‘We are extremely, repeat… extremely sensitive to subjects like cybersecurity and confidentiality and making sure the user remains in control,’ Pascal Ruch, head of Lexus Europe, tells CAR. ‘One thing you can really believe us on is that there will never be any kind of compromise there, and we will ensure zero risk.’
There is also, of course, the disadvantage of simply not having that physical connection. While there are many failsafes and dependencies in by-wire systems that can give the user peace of mind, some engineers still see it as a risk in certain circumstances. Engineers in Toyota’s Gazoo Racing divison, for example, don’t see any benefit in using a by-wire system; ‘one of our priorities is to keep the connection in a high-performance vehicle,’ says GR engineer Hiroyuki Yamada.
More than anything else, though, there is the simple point of whether it’s all that necessary. ‘From a customer’s perspective, there are some advantages for by-wire technology and we’re participating in this kind of technical development,’ says Starzynski, ‘but only time will tell us when the customer is actually ready for it. That is always the question.’