Hands on

It is your point of contact in the car. The means by which you direct the vehicle and, increasingly, a command system that allows you to control any number of additional functions within the vehicle. Although the earliest cars were controlled by a a steering lever or something resembling the handlebars of a bike, the steering wheel, has been the dominant feature inside the car for over 120 years.

It was French engineer Alfred Vacheron who developed a circular controller that enabled the steering angle to be transmitted in multiple rotations, and shortly after it was introduced, the steering wheel evolved into the worldwide standard.

Since then, although construction and materials have changed and technological advancements in steering technology have allowed the wheel to get smaller, visually the steering wheel has remained … a wheel.

The introduction of new technology like hydraulic power steering – which Audi introduced in the 1980s –  allowed wheels to became much smaller and more manageable, but along with the horn which was used to signal other road users and pedestrians, it remained a simple wheel. Then in 1991, the driver-side airbag became standard equipment adding another t=dimension to the wheel and the first buttons were also introduced for use in controlling the radio and sound system.

Since then, myriad designs have been developed, with more and more additional functions integrated into the wheel to allow the driver to control various vehicle functions while keeping their hands at the optimal ‘quarter to three’ position on the wheel.

Designers and engineers work very closely together on steering wheel design at Audi with the critical parameters being the rim diameter, the constructed space for the driver-side airbag, and the number of switches which must be reachable with either thumb without affecting the task of driving. Audi has also attempted to keep the rim’s geometry and centre as small and compact as possible, but that wasn’t always possible in the early days of airbags as the first generation ‘collision cushions’ were extremely bulky. As airbag technology has improved and airbags have been reduced in size, so too the centre of steering wheels has became smaller and more compact. 

For what is essentially a simple design at heart, a tremendous number of factors are considered with the modern Audi steering wheel.

Fixed sizes have become established for design and feel, with Audi establishing 375 millimetres as the scale for steering wheel diameters and the oval design of the rim profile is designed to naturally fit a closed hand.

The bias of the steering wheel depends on the driver’s sitting position and is between 17 and 24 degrees depending on the type of vehicle. In Audi SUVs for example, the angle is between 22 and 24 degrees, while in compact models it is 17 to 21 degrees. Regardless of the vehicle, the driver must be afforded a clear view of all displays and in all Audi models, the height and depth of the steering wheel can be adjusted plus or minus 30 millimetres so that each driver can find their optimum steering position.

Different materials and finishes have been employed over the years, and even variations on the wholly circular design, the distinctive flat-bottom design for example used in the Audi S and RS models. This design is reminiscent of racing wheels, the flat bottom allowing the driver easier entry and exit as well as adding to the sporty look of the interior.

Indeed in many race cars, the traditional circular steering wheel has long been a thing of the past, a more stylised ‘wheel’ design now adopted where the top and bottom of the circle have been deleted leaving just the grip areas at ‘nine’ and ‘three’. Such a paired down design though would not work in a more conventional vehicle. Given the need to often turn multiple revolutions, the absence of a ‘top’ or ‘bottom’ of the wheel would be a hindrance, rather than a help, but in the future, anything is possible.

Take for example the new Audi Q4 e-tron which sports a steering wheel that sets new standards in design, ergonomics, and functionality. The wheel rim is flattened on the top and bottom for the first time, giving the interior a more futuristic effect – very much along the lines of the modern racing car ‘wheel’ but in a far more practical configuration for road driving.

It integrates 18 functions in all, which can be operated for the first time via touch screens with a black panel look. Their function areas are back-lit to indicate which buttons are active and when they are inactive, the high-gloss black touch screens are virtually invisible. 

Small bumps on the wheel’s button functions form an outline between the touch screens and make them easier to use. When a person touches the screen with a finger, the system registers an action and gives haptic feedback when the driver gently presses with a certain force – the same technology as in the MMI touch in the centre console. With this operation concept, Audi is integrating technology into the steering wheel that is already familiar from smartphones and tablets, so apart from touch, there are also swipe movements for scrolling through navigation, media, and vehicle function menu lists.

Of course with the ongoing work in the area of autonomous driving, the cars of the future may not even need a steering wheel, but rather offer a completely autonomous experience. The benefits of the driverless car are well documented, but for the time being at least, there is no substitute for the feel of a steering wheel in your hands and the right piece of twisting mountain road snaking off into the distance.