It’s actually not quite an ordinary steering wheel – it lacks those round pieces at the top and bottom. But we will call him that anyway, because a suitable Czech equivalent for the English term “yoke” does not yet exist (although pilots might know the term “rams”). Plus, turning it actually steers the car, so it’s legit. Racing pilots drive their circuit specials in something similar, so it’s no coincidence that the powerful version of the RZ 550e F Sport got this technical gadget. But why exactly?
This whole technical miracle is called steer-by-wire. This means that there is no mechanical connection between the steering wheel and the front wheels. Instead of a classic steering column, there are wires, control units and electric motors to make the front wheels follow the instructions of your arms.
“This allows us to change the steering ratio depending on the speed and the driving situation,” explains Kenji Nishimura, assistant chief engineer of the RZ project. The same angle of the steering wheel when maneuvering in a parking lot will therefore cause a different angle of the wheels than on the highway, which allows you to tune the steering so that you have a quick response at lower speeds and stable steering at higher ones.
Photo: Lexus
The new “yoke” holds just as well as the steering wheel (that is, if you’re used to holding the steering wheel in a three-quarter to three position, otherwise you’re in trouble), but thanks to the variable steering gear, you won’t get your hands tangled up in Christmas. In no situation.
“At the same time, we can filter out unwanted effects, such as shocks on bumps or the effect of torque transfer,” adds Nishimura-san. The biggest challenge then was to keep enough feeling in the steering despite the quieting of traffic – so that you still feel in your hands that the wheels are connected to the road. “You can still feel the pull pulling on your hands in the steering wheel, but it’s muted so that you’re just aware of it and not bothered. You’ll also be aware when the front wheels start to slip.”
And the Lexus engineers really succeeded, because the new steering feels completely natural from the very first meters. We can easily slip around the post in the garages when parking and slip between the obstacles on the driveway. In corners, just a small movement of the forearm is enough and the RZ eagerly rushes to the apex, on the highway it sails undisturbed and does not require any major corrections from the driver.
Photo: Lexus
The missing upper part of the steering wheel rim freed up the view of the instrument panel. However, if you rest your hands on the upper or lower part of the wreath, you are out of luck.
You’ll get used to it almost immediately – that is, if you’re used to holding the steering wheel in the three-quarters-to-three position. Unlucky will be all lazy people who have their hand casually draped over the upper part of the wreath or placed on the lower part. But you won’t miss the round steering wheel otherwise, because the variable steering gear does not require any manual handling. When parking in tight spaces, when driving through a roundabout, or even when correcting a skid, you won’t get your hands tangled in Christmas.
The engineers tuned the steering to a range of 150°, i.e. not even half a turn to each side. “But then he tested Akio Toyoda’s car and demanded that the range be increased to 200°, so that even when driving fast on the circuit, the necessary corrections would be possible. The engineers, who already considered their work complete, had to start over and retune the entire system,” Kenji Nishimura explains the delay of the project, which was already completed two years ago, only to subsequently have to rework the entire set.
But now the system is really flawless. And also completely safe, for the homologation of the entire steer-by-wire, it was necessary to ensure a backup of the entire system (the components are therefore duplicated and also have a backup battery), so you don’t have to worry that the car would stop listening to you at a critical moment. “Since Lexus is the first to come out with this innovation, the homologation process was really challenging. But we managed it,” Nishimura-san nods his head with satisfaction.
Lexus is the first and the others will soon follow – Mercedes and Peugeot will soon introduce their system, other car companies are intensively continuing its development. Steering by wire is a basic prerequisite for fully autonomous driving. In addition, it also makes life easier for engineers – because you can easily move the steering wheel in the car from the left side to the right, or even to the middle, during the construction of the car. Or not to put it in the interior at all, when machines take over the world and they won’t even let us drive.
So let’s enjoy twisting the steering wheel while we still can. And the one in the Lexus RZ 550e F Sport does everything to draw you into the driving without disturbing you. And it does it so convincingly that you’ll wonder why other people are still reaching for the steering wheel like a monkey up a tree.
