Whenever I think about a Spartan array of instruments in a car, the VW-Beetle always springs to mind. In the above film, it did at least have a fuel gauge, which was later integrated into the speedometer. Indeed, the models before this one never had a fuel gauge at all. What one did, was to drive until the engine started to sputter, then change over to reserve and to keep one's eyes open for a filling station.
The combination shown in the above film, is of a completely mechanical nature. How the speedometer works can be seen here. The fuel gauge benefitted from the fact that the fuel tank was in the front luggage compartment. Thus, a float with a Bowden cable was sufficient.
The need for instruments actually dropped in the second half of the last century, because the cars of that time required less and less supervision, the VW-Beetle required very little anyhow. Still, in some particularly sporty cars people didn't want to do without a certain amount of instrumentation. At that time the rev-counter was a must, which by the way was also driven by a camshaft.
One only has to think back to Jaguar's legendary instrument-cluster, set in elegant wooden panelling, they were, apart from the wood, quite similar to that of an aircraft. Thereby, having a lot of gauges and dials is actually impractical because in theory, one would have to keep an eye on all of them at the same time. In fact the only really practical gauge, is the separate oil-pressure lamp, because then, a drop in oil-pressure is noticed more quickly.
There are five different places where the instruments are placed. Most frequently, they are placed behind the steering wheel, even though nowadays in Peugeot, they can be seen above the steering wheel. More seldom are they placed in the centre of the dashboard, where the passenger can better keep an eye on the speed. The most unfavourable position, is low down in the centre console.
The head-up display, where the most important information is in- or is projected onto the windscreen, is relatively new. The information can also be shown on a permanent- or pop-up small plastic screen. The display which is in the steering wheel itself, and combined with a jumble of buttons, is still in its infancy phase. In a lot of new models, there is still the analogue-looking clock in the centre of the dashboard.
The obvious digitisation has not been able to assert itself, although under the surface, it can hardly be avoided. Every car manufacturer would like to have an individual look, something that the suppliers can provide most economically by introducing digital displays. These displays can easily change depending on the driving mode or can be changed by the driver him/herself at will.
Round dials, even though they are not really there, are still much in demand, even if, e.g., in the Mercedes S-class, they have melted in with the general information to form a sort of display. Motorcycles on the other hand, have less space, they turn necessity into a virtue. A beautifully designed part can be seen in the next picture.