12 June 2020
12 June 2020
Step into the driver’s seat of a Mercedes-Benz, and it will invariably be the first thing you see and touch. So how often do you actually think about the technology, the safety or the just-right feel of a beautifully crafted steering wheel?
Probably not at all – and that’s just how Mercedes-Benz likes it. “Steering-wheel design is a world of its own and a very special challenge that is often underestimated,” says Hans-Peter Wunderlich, Creative Director, Interior Design at Mercedes-Benz, who has been designing steering wheels for around 20 years. “Besides the seat, the steering wheel is the only component in the vehicle with which we have intensive physical contact.
“The fingertips feel little things that we normally don’t notice. If an unevenness is disturbing or the steering wheel does not fit snugly in our hands, we don’t like it.”
Steering wheel design is a complex art
Over more than a century, designers such as Wunderlich have refined what was originally a very functional item – conceived simply to provide a mechanical connection between the driver and the front wheels – to a beautifully tactile, multi-function command centre that’s close to technical perfection. So close, you might not even give it a second thought.
Over the decades, the size, angle and shape have been obsessed over, a mix of premium tactile materials added, and – in recent years – myriad functions positioned intuitively to the driver’s fingertips, enabling the driver to keep eyes and attention firmly on the road ahead.
“The steering wheel rim is the secret kingmaker of a steering wheel. Its geometric design is a science in itself that cannot be found in any textbook,” says Wunderlich.
“The wreath must fit snugly in the hand. If it is a millimetre too much, it feels unpleasantly bulging. If it’s a millimetre too little, it feels like it’s starved. And that impression then clouds the overall feel of the car.”
Take the steering wheel in the newest addition to the Mercedes-Benz compact SUV range, the GLB. It’s a beautiful example of a tool where function and form seamlessly unite.
At the most intimate level, the circular rim falls ideally to the driver’s hand and feels just right, its movement perfectly weighted to provide optimum feedback with minimal fatigue.
But for drivers yearning for extra connection and control, the opportunities are almost limitless. Cruise control is a given in most modern vehicles, but the ability to use simple and intuitive swipe-and-tap motions to control audio, phone and navigation functions, even changing ambient lighting and drive modes, puts a suite of functions – previously found in multi-layered, attention-sapping menus – literally at the driver’s fingertips.
The first steering wheel features
Obviously, it wasn’t always this way; pre-1900, the very first cars contained a simple steering tiller or lever that mimicked the motion of pulling a horse’s rein left or right. The first steering ‘wheel’ was fitted to a car in 1894 for the world’s inaugural automobile race, from Paris to Rouen. The Panhard & Levassor model was powered by a Daimler engine and its rudimentary circular wheel gave Frenchman Alfred Vacheron an advantage because the steering force could be distributed across a wider range of movement than a simple lever.
Surprisingly, the very first multi-function steering wheel made its debut shortly after, in the very early 1900s, when additional levers were fixed to the wheel to regulate ignition timing and air/fuel mixture, which later became redundant as engine technology improved. It would be another 90 years before the multi-function wheel would return!
The other key function to which the driver required quick access was a horn, and this started out as a bulb-type horn mounted on the steering wheel rim, later replaced by a klaxon-style horn on the steering wheel hub. A horn ring was mounted on the steering wheel spokes in the 1920s, which became the standard until the 1970s when a push-button was integrated.
Another important part of the steering wheel story was the development in the 1940s and ‘50s of turn indicators and gearshift levers appended to the steering wheel column, to which headlight controls were later added. Power steering was also added in the 1950s, making its debut in the Mercedes-Benz range in 1958 in the 300 saloon.
Crucially, a new safety steering wheel with a large, deformable baffle plate and collapsible steering column were devised by Mercedes-Benz engineers in 1959 to better protect the driver in a collision. Steering wheel construction was further refined in the 1970s and ‘80s, decreasing the forces travelling through the assembly in an impact and ensuring the steering wheel rim couldn’t break.
It was in 1981 that a frontal airbag was first fitted in the steering wheel of a Mercedes-Benz S-Class, the first time an airbag had been integrated with automatically tensioning seatbelts in a collision.
It is amazing when looking at the myriad functions and controllers on a modern steering wheel to consider that from the early 1900s up to the 1970s, most steering wheels housed nothing more elaborate than the horn. But that was all about to change and in December 1975, the Mercedes-Benz 450 SEL 6.9 was one of the first automobiles to be equipped with a so-called cruise control system as standard, accessible via a stalk on the steering column.
It wasn’t until the second half of the 1990s that micro-computer technology progressively allowed the incorporation of buttons into the steering wheel interface to take fingertip control of audio, cruise control, phone and navigation functions.
In 2016, Mercedes-Benz began to integrate touch-sensitive controllers that enable smartphone-like swipe-and-touch control over both the driver’s display and the central multimedia screen. The ‘haptic’ controllers are utilised as an integral part of the advanced MBUX system across an array of current passenger models, including the GLB compact SUV.
From humble steering wheel to “capacitive command centre”
However, even as this handy and intuitive system continues to bring first-time buyers to the brand, Mercedes-Benz is in the process of shifting the game again, this time with the “capacitive command centre” set to make its debut in the next generation of the venerable E-Class family.
This brings touch-sensitive capability not only to each of the buttons housed on the steering wheel, but also to the steering wheel itself, which incorporates sensors in the rim to detect if the driver has contact with the wheel. This is useful in semi-autonomous driving situations, in which the vehicle must be able to detect that the driver is in position to take command of the vehicle.
“It is the most beautiful steering wheel we have ever built,” says Wunderlich of the advanced E-Class tiller. “The proportions of the airbag, spokes and rim are absolutely harmonious.”
By Steve Colquhoun